Discussion of“Reliability Evaluation of Cross-Hole Sonic Logging for Bored Pile Integrity”by D.Q.Li,L.M.Zhang,and
W.H.Tang
September2005,V ol.131,No.9,pp.1130–1138.
DOI:10.1061/?ASCE?1090-0241?2005?131:9?1130?
Joram M.Amir,F.ASCE1
1Chairman,https://www.doczj.com/doc/339609018.html, Ltd.,85Hanassi St.,Herzlia46399,Israel.
E-mail:imamir@https://www.doczj.com/doc/339609018.html,
During the last decade cross-hole sonic logging,alternatively re-ferred to as ultrasonic cross-hole testing of piles?ASTM2002?, has established itself as the preferred method for quality control of bored piles?alias caissons and drilled shafts?.While the prin-ciples lying behind the test are now well understood,there is still disagreement as to the number of access tubes that are necessary to perform the test.This subject has a clear economic conse-quence:While increasing the number of access tubes in a pile may improve the test’s?aw detection capability,these tubes carry a price tag in material,workmanship,and increased testing costs. The effort made by the authors to determine the optimal number of access tubes for each situation should therefore be com-mended.
For the paper presented to qualify as a practical guide,it has to ful?ll certain conditions:
1.The work has to address the technical features speci?c to the
test.
2.It should be based on reasonable assumptions,commensurate
with observed facts and common knowledge.
3.The mathematical treatment must be rigorous.
Being guided by these criteria,the discusser would like to raise certain reservations related to the methodology followed by the authors.These are presented in the following paragraphs.
Technical Features
Typically,two distinct parameters are measured in the ultrasonic cross-hole test:?rst arrival time?FAT?and relative energy ?ASTM2002?.Each of these has its special signi?cance in the interpretation of the test results.Certain?aws are better expressed in FAT terms,while others have more in?uence on the relative energy.It is regrettable,therefore,that in discussing inspection probability the authors do not mention which of these two they refer to.
Furthermore,the heterogeneity of concrete may cause test re-sults to exhibit large scatter?Amir et al.2004?.Under these con-ditions,a defect of a given size may escape detection when its effect on the test results is of the same order as the scatter.In such a noisy environment,the de?nition of what constitutes an anomaly is rather arbitrary,with different codes providing differ-ent prescriptions.The Chinese code?MOC2003?,for instance, de?nes as anomalous any result in which the apparent wave ve-locity deviates from the mean by??,or a prescribed number of standard deviations.The authors tacitly circumvent this crucial problem by assuming those detection thresholds are independent of the signal-to-noise ratio.
Validity of Assumptions
The authors make several assumptions,among which the most important are
1.On the basis of Fleming et al.?1992?,the authors assume that
a defect may occupy,with equal likelihood,any position
within the pile cross section.However,a careful study of the numerous photographs provided by Fleming et al.?1992?clearly shows that most of them depict defects in the periph-ery.O’Neil?1991?explains this phenomenon,to which many practitioners can testify from personal experience?Fig.1?,by the interaction of the rising concrete column and the slurry with the surrounding soil,groundwater,temporary casing, and reinforcement cage—all located at the pile’s periphery.
The widespread usage of the terms“necking”or“waisting”
in describing pile integrity attests to this phenomenon.
2.The authors claim that what they de?ne as the“encountered
probability”of a defect depends only on its size.Evidently, this is necessarily incorrect:While an air void of a few mil-limeters caused by tube debonding is clearly detected,a de-fect two orders of magnitude larger may escape detection if it is located farther away from a tube.Thus,defect position is not less and maybe more important than its size.
To illustrate this point,a?nite element simulation of the Fig.1.Typical defect in bored pile constructed with polymer slurry
cross-hole test was run,using the Plaxis program,for three cases:no defect;circular defect,5wavelengths in diameter halfway between the transmitter and receiver;and circular defect,5wavelengths in diameter,close to the transmitter.The results of the simulation,presented as horizontal dis-placement versus time,are reasonably similar to those ob-tained in a real test.The results ?Fig.2?show that a defect halfway between the tubes is hardly discernible,while an identical one located close to the emitter ?or in fact to the receiver ?is easily detected:the FAT is at least 20%larger,and the maximum amplitude 75%?or 12dB ?smaller.
3.
In de?ning the detection probability for a defect in a pile ?Eq.4?,the authors adopt results developed for cracks in metal.The validity of this analogy is,however,not self-evident.Concrete in piles,unlike metal,is far from homogeneous,and typical defects in piles are not well-de?ned features but of rather fuzzy character.Thus,the detection threshold of defects in piles must be much higher.
d.The authors assume that waves propagate in straight lines.While this may be true for homogeneous media,it is not necessarily so in heterogeneous materials like concrete ?Santamarina et al.2001?.Even in a homogeneous medium with inclusions of foreign materials,waves will travel in curved paths to go around those inclusions and minimize arrival time ?Fermat’s postulate ?.
Analysis
In Eq.1the authors express inspection probability P ?x ?as a prod-uct of encountered probability P ?E ?x ?and the detection probabil-ity P ?D ?E ,x ?,both dependent on defect size x .Since the law of multiplication is only applicable to statistically independent prob-abilities ?Bulmer 1967?,the use of Eq.1is not justi?ed.
Summary
The treatise presented by the authors appears to be based on sim-plifying assumptions that seem to contradict both empirical evi-dence and accepted principles.Moreover,the statistical treatment of the problem is ?awed,and above all,the authors do not address the speci?c parameters that characterize real-life cross-hole tests.As a result,the validity of their results is questionable,and extra caution is deemed necessary in the application of their conclu-sions to practical situations.
References
Amir,J.M.,Amir,E.I.,and Felice,C.W.?2004?.“Acceptance criteria for bored piles by ultrasonic testing.”Proc.,Int.Conf.on Application of Stress Wave Theory to Piling ,Kuala Lumpur.
Bulmer,M.G.?1967?.Principles of statistics ,Dover,New York,17.O’Neill,M.W.?1991?.“Construction practices and defects in drilled shafts.”Transportation Research Record ,Washington,D.C.,6–14.Santamarina,J.C.,Klein,A.,and Fam,M.A.?2001?.Soils and waves ,Wiley,Chichester,212.
Fleming,W.G.K.,Weltman,A.J.,Randolph,M.P.,and Elson,W.K.?1992?.Piling engineering ,2nd Ed.,Wiley,New York.
Ministry of Construction ?MOC ?.?2003?.Technical code for testing of building foundation piles (JGJ 106-2003),Beijing.
Closure to “Reliability Evaluation of
Cross-Hole Sonic Logging for Bored Pile Integrity”by D.Q.Li,L.M.Zhang,and W.H.Tang
September 2005,V ol.131,No.9,pp.1130–1138.
DOI:10.1061/?ASCE ?1090-0241?2005?131:9?1130?
D.Q.Li 1;L.M.Zhang 2;and W.H.Tang 3
1
Associate Professor,State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan Univ.,Wuhan,China;formerly,Postdoctoral Research Associate,Hong Kong Univ.of Science and Technology,Kowloon,Hong Kong.E-mail:dianqing@https://www.doczj.com/doc/339609018.html, 2
Associate Professor,Dept.of Civil Engineering,Hong Kong Univ.of Science and Technology,Clear Water Bay,Kowloon,Hong Kong.E-mail:cezhangl@ust.hk 3
Chair Professor,Dept.of Civil Engineering,Hong Kong Univ.of Science and Technology,Clear Water Bay,Kowloon,Hong Kong.E-mail:wtang@ust.hk
The authors are grateful to Dr.Joram M.Amir for his thoughtful discussion.
Technical Features
The authors did not consider the detection capability of cross-hole sonic logging ?CSL ?directly from the technical features of CSL such as ?rst arrival time and relative energy.Instead,the detection probability for bored piles considered in this paper is based on past CSL performance.A detection probability function by Yang and Trapp ?1975?is used,and the minimum detectable void size and the detectable void size with certainty are selected based
on
Fig.2.Pile with no defect ?thin line ?,with defect halfway between tubes ?a ?,and with defect close to transmitter ?b ?
past CSL detection performance for bored piles?Table2in the
paper?.
The discusser proposes to explore the detection probability of
CSL based on technical features of CSL.This can certainly add
physical understanding to the issue.This approach may at the
same time,as pointed out by the discusser,be rendered ineffective
by the heterogeneity of concrete and locations of anomalies?see
Fig.2of the Discussion?.
Validity of Assumptions
As mentioned by O’Neill?1991?,defects such as necking and soil
inclusions may be located at a pile’s periphery,while defects such
as voids and cracks can be located at any position within the pile
shaft.For simplicity,it is assumed that the defect location is uni-
formly distributed over the cross section of the pile in the paper.
This assumption may somewhat overpredict the encountered
probability of CSL.
The concepts of encountered probability and inspection prob-
ability cannot be confused.The chance that a defect may be found
by an integrity test is quanti?ed through the inspection probability
rather than the encountered probability alone.This is an important
point that this paper attempts to clarify.Encountered probability
depends only on the defect size and the arrangement of access
tubes.The encountered probability referred to by the discusser is
actually the inspection probability as de?ned by the authors.
The effect of defect location on the inspection probability has
been taken into consideration through the detection probability
de?ned in this study,which is illustrated in Fig.4in the paper.In
Fig.4,y is the distance from the center of the defect to the chord
and is used to account for the effect of defect location.The effect
is quanti?ed in the subsequent analysis through Fig.5and Eqs.?12?and?13?in the paper.For instance,for a defect with a diam-eter of200mm,the detection probability is1.0for the case when
the defect is located at the center of the signal path and0for the
case when the defect is randomly located within the pile cross
section.Obviously,the detection probability can differ consider-
ably based on the difference in the defect location,though the
defect size remains the same.Consequently,the probability that an inspection will?nd a defect can differ considerably.
The detection probability function shown in Eq.?4?in the paper is obtained based on data from ultrasonic inspection of fatigue cracks in metal structures?Yang and Trapp1975?.With regard to integrity testing for large-diameter bored piles,no de-tection probability functions have ever been reported in the litera-ture.In this paper,Eq.?4?is assumed to apply equally well to CSL for large-diameter bored piles.It should be noted that the detection thresholds for defects have been determined based on experimental results of CSL for large-diameter bored piles rather than results of cracks in metals.The detection thresholds of de-fects are133.3and200mm in Eqs.?12?and?13?for the two cases considered in the paper.Both of them are considerably higher than10mm for cracks in metal structures?Ichikawa1985?or1.0mm for magnetic inspection?Guedes Soares and Garbatov 1996?.
Following Hassan and O’Neill?1998?,the authors assumed that a cross-hole sonic logging test can scan the path between the two access tubes with a width of about2?,where?is the wave length.The discusser is correct when he says that waves may travel in curved paths to go around inclusions.This will affect both the encountered probability and the detection probability and is certainly worthy of further study.Analysis
A defect inspection requires the intersection of two events, namely?1?the defect must be encountered,and?2?the defect must be detected.Eq.?1?describes that the intersection probabil-ity can be expressed as the product of the encountered probability and the conditional probability that the defect will be detected if it has been encountered?that is,the detection probability?.Clearly, both the encountered probability and detection probability are re-lated to the defect size.The inspection probability will be zero if the defect is not encountered or if the defect is encountered but not detected by the CSL.
Summary
The major points in the discussion seem to have arisen from confusion between the encountered probability and the inspection probability.A thrust of this paper is to clarify the concepts of encountered probability,detection probability,and inspection probability.The paper provides a quantitative guidance for the number of access tubes for CSL based on past CSL performance. Indeed some assumptions are made for the analysis of the en-countered probability and detection probability.The results pre-sented in this paper are accordingly valid to the degree these assumptions are met.
References
Guedes Soares,C.,and Garbatov,Y.?1996?.“Fatigue reliability of the ship hull girder accounting for inspection and repair.”Reliab.Eng.
Syst.Saf.,51?3?,341–351.
Hassan,K.M.,and O’Neill,M.W.?1998?.“Structural resistance factors for drilled shafts with minor defects.”Final Rep.,Phase I,Dept.of Civil and Environmental Engineering,Univ.of Houston,Houston. Ichikawa,M.?1985?.“A theoretical study of defect detection probability of nondestructive inspection.”Reliability Engineering,10,175–182. O’Neill,M.W.?1991?.“Construction practices and defects in drill shafts.”Transportation Research Record,Washington,D.C.,6–14. Yang,J.N.,and Trapp,J.W.?1975?.“Reliability analysis of fatigue-critical aircrafts structures under random loading and periodic inspec-tions.”Technical Rep.,AFML-TR-75-29,Air Force Materials Laboratory,Washington,D.C.
Discussion of“Comparison of Interface Shear Strength of Soil Nails Measured by Both Direct Shear Box Tests and Pullout Tests”by Lok-Man Chu and Jian-Hua Yin September2005,V ol.131,No.9,pp.1097–1107.
DOI:10.1061/?ASCE?1090-0241?2005?131:3?1097?
K.S.Li1and S.R.Lo2
1Director,Victor Li and Associates Ltd.,Hong Kong.
2Associate Professor,School of Aerospace,Civil and Mechanical Engineering Univ.of New South Wales at ADFA,Australia.
Although several tens of thousands of soil nails are installed an-nually to stabilize slopes in Hong Kong,there have been very few,if any,local detailed laboratory studies,on the pullout resis-
tance soil nails under Hong Kong conditions.The authors’study is a signi?cant step toward a better understanding of the factors controlling pullout resistance of soil nails.
In Hong Kong,soil nails are commonly installed in existing slopes to stabilize soil and sometimes they are installed in newly formed cut slopes for temporary excavations.The construction method involves forming a drillhole,inserting a deformed bar, and grouting gravity.
When some preliminary?ndings of this paper were presented earlier by Chu and Yin?2004?in a seminar in Hong Kong,Li made the following remarks,which are believed to be applicable to the present paper.
Geotechnical structure behaviors are highly dependent on the method of construction.In the study of a soil nail’s behavior,it is of paramount importance to mimic its method of construction.
When a stable drillhole is formed,the radial stress in the vi-cinity of the soil face will be close to zero,which is completely different from the test conditions devised by the authors in which the applied stress was exerted only after installation of the model soil nail.Consequently,the results presented by the authors may
not necessarily be representative of the actual behavior in the
?eld.
In this discussion,the writers would like to elaborate the above
points further and share some thoughts on possible mechanisms
by which soil nails develop their pullout resistance.In this dis-
cussion the term“soil nail”includes the annulus of grout around
the deformed bar.The stress state around a drillhole is illustrated
in Fig.1.Before a drillhole is formed,the soil at the drillhole location is subjected to the overburden pressure?v??Fig.1?a??. After a drillhole has been formed,stability of the hole is main-
tained by the arching effect,and hence the radial stress at the soil
face must be close to zero?see Fig.1?b??.After installation,a
small effective radial stress will be reintroduced with gravity
grouting.In other words,both the stress path and the stress state
in the vicinity of the nails in the?eld are signi?cantly different
from that in the laboratory study presented by the authors.
If the initial stress acting normal to the soil nail is small,it is
interesting to speculate the possible mechanisms for the develop-
ment of pullout resistance.
Soil Dilatancy
During a pull-out test,soils in the vicinity of a nail will be subject
to signi?cant shearing.The additional normal stress induced by
the mechanism of constrained dilatancy?Lo2003?will cause fric-
tion,and hence pullout resistance will develop along the soil nail.
Preliminary numerical studies using Mohr-Coulomb elastic-
plastic model with a nonassociative?ow rule presented by Lo ?2002?clearly showed the signi?cance of dilatancy.Loose soils have a small potential for soil dilation,and one may expect soil nails installed in such soils to have low pull-out resistance.How-ever,?eld data indicate that soil nails installed in loose?ll,for instance,can sometimes develop a signi?cant pullout resistance. Other factors must contribute to this outcome.
Interface Dilation
Drillholes installed using techniques in Hong Kong have over-break.Such drillholes will generate interface dilatancy during shearing in a manner similar to the development of side resistance in a rock socketed pile in weak rock.
Physical Bonding
When the drillhole is grouted,cement grout will permeate into the soils.The soil nail and the soils around it are mechanically bonded by the cement grout.Pullout resistance may then develop as a result of adhesion between the soil/soil-nail interface.Alter-natively,the shear plane may move into the virgin soil,leading to a signi?cant,larger“equivalent nail diameter”and thus a signi?-cantly larger pullout resistance.
To obtain meaningful results that can lead to the improved soil nail design and construction practices in Hong Kong,it is impor-tant that laboratory tests be devised to model the actual?eld conditions and to ascertain which one or combination of the above mechanisms are dominant.For instance,if bonding is im-portant,one may perhaps recommend a higher water-cement ratio and the use of retarder for the cement grout,and a longer grouting period to encourage better permeation of the material into the soils.Pressure grouting may also be used to either improve
grout Fig.1.Stress state around drillhole
permeation or to introduce higher normal stress at the soil-nail interface.
According to data presented by the authors,the pullout resis-tance of soil nails increases approximately linearly with applied stress.Additional studies,both laboratory and numerical,are needed before making recommendations for the current design practice for the following reasons:
1.The issues of soil arching and constrained dilatancy should
be addressed as discussed above.In this respect,it is inter-esting to note the design practice of tunnel lining.Tunnel engineers do not increase the thickness of tunnel lining for a deep tunnel in proportion with the thickness of overburden above a tunnel.Soil relaxation that occurs after the formation of a drillhole and before the grouting of the soil nail will also affect the normal stress acting on installed soil nails.The in?uence of the arching effect on pullout resistance can be studied by exerting the applied stress?rst before installing the model soil nail and varying the thickness of soil cover above the test nail.
2.Because the nails are signi?cantly stiffer than the surround-
ing soil,the vertical stress in the vicinity of the nail may be signi?cantly higher than the applied stress.
3.The authors installed the test soil nails using coring methods.
In Hong Kong,soil nails are installed by percussive method, and soil cuttings are?ushed out of the drillholes with com-pressed air.This is expected to create a rougher drillhole with higher overbreak and hence more signi?cant interface dila-tion than would be created using coring method.
4.In the?eld,soil nails are installed in an inclined position to
enable cement grout to stay in the drillhole and produce a small hydraulic head to facilitate permeation of cement grout into the soil.In the authors’study,the test nails are installed horizontally and permeation of cement grout into the soil may not be as effective as in the prototype soil nails.
5.The use of soil nails in Hong Kong is not restricted to steep
slope.For gentler slopes,the determination of?v?becomes problematic.The current Hong Kong practice assumes ?v???h for soil nails installed in a uniform soil above the ground water table?see Fig.1?a??.This assumption is true only for horizontal ground.It will be useful if researchers can perform numerical analyses to calibrate current Hong Kong practice and,if necessary,develop an alternative simple cal-culation model?maybe with the aid of design charts?for the design of soil nails.
References
Chu,L.M.,and Yin,J.H.?2004?.“Testing study on the interface be-tween soil and soil nail.”Proc.,24th Annual Seminar:Recent Ad-vances in Geotechnical Engineering,Geotechnical Division,the Hong Kong Institution of Engineers,Hong Kong.
Lo,S.R.?2002?.“Nail pullout:The in?uence of dilatancy angle.”Lecture Notes for Seminar and Workshop on Geotechnical Modeling,Centre for Research and Professional Development,123–127.
Lo,S.-C.R.?2003?.“The in?uence of constrained dilatancy on pullout resistance of geosynthetic strap reinforcement.”Geosynthet.Int., 10?2?,47–55.Closure to“Comparison of Interface Shear Strength of Soil Nails Measured by Both Direct Shear Box Tests and Pullout Tests”by Lok-Man Chu and Jian-Hua Yin
September2005,V ol.131,No.9,pp.1097–1107.
DOI:10.1061/?ASCE?1090-0241?2005?131:9?1097?
Lok-Man Chu1and Jian-Hua Yin2
1Dept.of Civil and Structural Engineering,The Hong Kong Polytechnic Univ.,Hung Hom,Kowloon,Hong Kong,China.
2Professor and Head of Soil Mechanics Laboratory,The Hong Kong Polytechnic Univ.,Dept.of Civil and Structural Engineering,Hung Hom,Kowloon,Hong Kong,China.E-mail:ceihvin@https://www.doczj.com/doc/339609018.html,.hk
The authors would like to express sincere thanks to the two dis-cussers for their insightful discussion on our paper and valuable suggestions for further studies.
The discussers make two remarks on our research project:?1?the construction process of a soil nail should have been simulated in the laboratory soil pullout tests and?2?a vertical pressure was applied?rst before the installation of the soil nail in the test so that the stress release in drilling of the hole was not considered and the behavior measured in the lab might not be representative of the actual behavior in the?eld.
The authors agree with the discussers that the simulation of the soil nail installation process is very important.The authors would like to mention that the study presented in the paper was not intended to simulate the installation process but rather to measure the fundamental shear strength of the interface between the ce-ment grout?soil nail surface?and the surrounding soil.The per-formance of a soil nail in a slope,including the elements of the construction process,such as drilling a hole and grouting,is con-sidered to be a boundary value problem.A numerical method based on the continuous mechanics shall be used to solve this boundary value problem.This method shall take into account of stress equilibrium,strain-displacement compatibility,proper con-stitutive equations for the soil and the soil-nail interface,and proper boundary conditions.Here,the constitutive equations for the soil and the soil-nail interface are for the fundamental behav-ior,also called elementary behavior.The behavior measured in our laboratory soil nail pullout tests is,in fact,the elementary behavior of the soil-nail interface.The soil nail pullout tests in the paper were very much like direct shear box tests.The results from such pullout tests can be used to obtain the fundamental?or el-ementary?soil-nail interface shear strength parameters.
The authors are happy to report that a new study has been carried out,using a new soil nail pullout box with comprehensive instrumentation,to simulate the soil nail installation process and to investigate the in?uence of overburden pressure,the degree of water saturation,and cement slurry pressure grouting.Based on the new test results,a new paper titled“Laboratory Testing Study on the In?uence of Overburden Pressure on Soil Nail Pullout Resistance in Compacted Completely Decomposed Granite Fill”by Li-Jun Su,Terence C.F.Chan,Herman Y.K.Shiu,S.L.Chiu, and Jian-Hua Yin has been submitted to this journal for review and possible publication.This new study simulated the perfor-mance of a segment of a soil nail in the actual?eld condition.In
this new paper,the whole construction process and soil nail pull-out,including the soil pressure caused by hole drilling?stress release?and changes caused by grouting and soil nail pull out, was closely monitored.The results from this new study indicate that the soil nail pullout resistance is not in?uenced by the over-burden pressure.This new paper will address some of the discuss-ers’concerns in greater detail.
The discussers present the mechanisms that affect the pullout resistance of a soil nail in the?eld—that is,dilatancy of soil, dilatancy of the nail-soil interface,and physical bonding.The authors appreciate the insightful analysis of the mechanisms. These mechanisms have been mostly investigated in our new studies using a new soil nail pullout box.
The discussers observe that the soil nail pullout resistance from tests presented in the paper increased with the applied ver-tical stress.This is true for elementary tests because the old pull-out box tests were similar to direct shear box tests.The discussers make suggestions for further studies on a few important issues:?1?the issues of soil arching and constrained dilatancy,?2?the stress concentration on the soil nail as it is stiffer,?3?different coring methods such as the percussive method,?4?inclination of a soil nail hole with a small gravity head for grouting pressure, and?5?the determination of the vertical effective stress on the soil nail surface installed in a slope.The authors appreciate the valuable suggestions.The authors would like to report that we conducted a preliminary study of issues?2?and?3?.Issues?1?and ?4?have been investigated in our new study using a new soil nail pullout box.Issue?5?has not been addressed by us but has been pointed out by other researchers as well.
分考点1 表示时间的介词 Point 1 at, in, on 的用法 （1）at 的用法 At 表示时间点，用于具体的时刻（几点，正午，午夜，黎明，拂晓，日出，日落等），或把某一时间看作某一时刻的词之前以及某些节假日的词之前。 at 6：00 在6点钟 At noon 在中午 At daybreak 在拂晓 At down 在黎明 At Christmas 在圣诞节 【特别注意】在以下的时间短语中，at 表示时间段。 At dinner time 在（吃）晚饭时 At weekends/ the weekend 在周末 （2）in 的用法 ①表示时间段，与表示较长一段时间的词搭配，如年份，月份，季节，世纪，朝代，还可以用于泛指的上午、下午、傍晚等时间段的词前。 In 2009 在2009年 In April 在四月 In the 1990s 在20世纪90年代 In Tang Dynasty 在唐朝 In the morning在上午 ②后接时间段，用于将来时，表示“在一段时间之后”。 The film will begin in an hour. 电影将于一个小时之后开始。 【特别注意】当时间名词前有this，that，last，next，every，each，some等词修饰时，通常不用任何介词。 This morning 今天上午last year 去年 （3）on 的用法 ①表示在特定的日子、具体的日期、星期几、具体的某一天或某些日子。 On September the first 在9月1号 On National Day 在国庆节 We left the dock on a beautiful afternoon. 我们在一个明媚的下午离开了码头。 ②表示在具体的某一天的上午、下午或晚上（常有前置定语或后置定语修饰）。 On Sunday morning 在星期日的早上 On the night of October 1 在10月1号的晚上 【特别注意】“on +名词或动名词”表示“一...就...”. On my arrival home/ arriving home, I discovered they had gone. 我一到家就发现他们已经离开了。 Point 2 in，after 的用法 In 和after都可以接时间段，表示“在...之后”，但in 常与将来时连用，after 常与过去时连用。 We will meet again in two weeks.
英语介词用法大全 TTA standardization office【TTA 5AB- TTAK 08- TTA 2C】
介词（The Preposition）又叫做前置词，通常置于名词之前。它是一种虚词，不需要重读，在句中不单独作任何句子成分，只表示其后的名词或相当于名词的词语与其他句子成分的关系。中国学生在使用英语进行书面或口头表达时，往往会出现遗漏介词或误用介词的错误，因此各类考试语法的结构部分均有这方面的测试内容。 1. 介词的种类 英语中最常用的介词，按照不同的分类标准可分为以下几类： (1). 简单介词、复合介词和短语介词 ①.简单介词是指单一介词。如： at , in ,of ,by , about , for, from , except , since, near, with 等。②. 复合介词是指由两个简单介词组成的介词。如： Inside, outside , onto, into , throughout, without , as to as for , unpon, except for 等。 ③. 短语介词是指由短语构成的介词。如： In front of , by means o f, on behalf of, in spite of , by way of , in favor of , in regard to 等。 (2). 按词义分类 {1} 表地点（包括动向）的介词。如： About ,above, across, after, along , among, around , at, before, behind, below, beneath, beside, between , beyond ,by, down, from, in, into , near, off, on, over, through, throught, to, towards,, under, up, unpon, with, within , without 等。 {2} 表时间的介词。如： About, after, around , as , at, before , behind , between , by, during, for, from, in, into, of, on, over, past, since, through, throughout, till(until) , to, towards , within 等。 {3} 表除去的介词。如： beside , but, except等。 {4} 表比较的介词。如： As, like, above, over等。 {5} 表反对的介词。如： againt ,with 等。 {6} 表原因、目的的介词。如： for, with, from 等。 {7} 表结果的介词。如： to, with , without 等。 {8} 表手段、方式的介词。如： by, in ,with 等。 {9} 表所属的介词。如： of , with 等。 {10} 表条件的介词。如：
to与for的用法和区别 一般情况下, to后面常接对象; for后面表示原因与目的为多。 Thank you for helping me. Thanks to all of you. to sb.表示对某人有直接影响比如，食物对某人好或者不好就用to; for表示从意义、价值等间接角度来说，例如对某人而言是重要的，就用for. for和to这两个介词，意义丰富，用法复杂。这里仅就它们主要用法进行比较。 1. 表示各种“目的” 1. What do you study English for? 你为什么要学英语？ 2. She went to france for holiday. 她到法国度假去了。 3. These books are written for pupils. 这些书是为学生些的。 4. hope for the best, prepare for the worst. 作最好的打算，作最坏的准备。 2．对于 1．She has a liking for painting. 她爱好绘画。 2．She had a natural gift for teaching. 她对教学有天赋/ 3．表示赞成同情，用for不用to. 1. Are you for the idea or against it? 你是支持还是反对这个想法？ 2. He expresses sympathy for the common people.. 他表现了对普通老百姓的同情。 3. I felt deeply sorry for my friend who was very ill. 4 for表示因为，由于（常有较活译法） 1 Thank you for coming. 谢谢你来。 2. France is famous for its wines. 法国因酒而出名。 5．当事人对某事的主观看法，对于（某人），对…来说（多和形容词连用）用介词to，不用for.. He said that money was not important to him. 他说钱对他并不重要。 To her it was rather unusual. 对她来说这是相当不寻常的。 They are cruel to animals. 他们对动物很残忍。 6．for和fit, good, bad, useful, suitable 等形容词连用，表示适宜，适合。 Some training will make them fit for the job. 经过一段训练，他们会胜任这项工作的。 Exercises are good for health. 锻炼有益于健康。 Smoking and drinking are bad for health. 抽烟喝酒对健康有害。 You are not suited for the kind of work you are doing. 7. for表示不定式逻辑上的主语，可以用在主语、表语、状语、定语中。 1．It would be best for you to write to him. 2．The simple thing is for him to resign at once. 3．There was nowhere else for me to go. 4．He opened a door and stood aside for her to pass.
英语常用介词用法与辨析 ■表示方位的介词：in, to, on 1. in 表示在某地范围之内。如： Shanghai is/lies in the east of China. 上海在中国的东部。 2. to 表示在某地范围之外。如： Japan is/lies to the east of China. 日本位于中国的东面。 3. on 表示与某地相邻或接壤。如： Mongolia is/lies on the north of China. 蒙古国位于中国北边。 ■表示计量的介词：at, for, by 1. at表示“以……速度”“以……价格”。如： It flies at about 900 kilometers a hour. 它以每小时900公里的速度飞行。 I sold my car at a high price. 我以高价出售了我的汽车。 2. for表示“用……交换，以……为代价”。如： He sold his car for 500 dollars. 他以五百元把车卖了。 注意：at表示单价(price) ，for表示总钱数。 3. by表示“以……计”，后跟度量单位。如： They paid him by the month. 他们按月给他计酬。 Here eggs are sold by weight. 在这里鸡蛋是按重量卖的。 ■表示材料的介词：of, from, in 1. of成品仍可看出原料。如： This box is made of paper. 这个盒子是纸做的。 2. from成品已看不出原料。如： Wine is made from grapes. 葡萄酒是葡萄酿成的。 3. in表示用某种材料或语言。如： Please fill in the form in pencil first. 请先用铅笔填写这个表格。 They talk in English. 他们用英语交谈(from 。 注意：in指用材料，不用冠词；而with指用工具，要用冠词。请比较：draw in penc il/draw with a pencil。 ■表示工具或手段的介词：by, with, on 1. by用某种方式，多用于交通。如by bus乘公共汽车，by e-mail. 通过电子邮件。
with的用法大全----四级专项训练with结构是许多英语复合结构中最常用的一种。学好它对学好复合宾语结构、不定式复合结构、动名词复合结构和独立主格结构均能起很重要的作用。本文就此的构成、特点及用法等作一较全面阐述，以帮助同学们掌握这一重要的语法知识。 一、 with结构的构成 它是由介词with或without+复合结构构成，复合结构作介词with或without的复合宾语，复合宾语中第一部分宾语由名词或代词充当，第二部分补足语由形容词、副词、介词短语、动词不定式或分词充当，分词可以是现在分词，也可以是过去分词。With结构构成方式如下： 1. with或without-名词/代词+形容词; 2. with或without-名词/代词+副词; 3. with或without-名词/代词+介词短语; 4. with或without-名词/代词+动词不定式; 5. with或without-名词/代词+分词。 下面分别举例：
1、 She came into the room，with her nose red because of cold.(with+名词+形容词，作伴随状语) 2、 With the meal over ， we all went home.(with+名词+副词，作时间状语) 3、The master was walking up and down with the ruler under his arm。(with+名词+介词短语，作伴随状语。) The teacher entered the classroom with a book in his hand. 4、He lay in the dark empty house，with not a man ，woman or child to say he was kind to me.(with+名词+不定式，作伴随状语) He could not finish it without me to help him.(without+代词 +不定式，作条件状语) 5、She fell asleep with the light burning.(with+名词+现在分词，作伴随状语) 6、Without anything left in the cupboard， she went out to get something to eat.(without+代词+过去分词，作为原因状语) 二、with结构的用法 在句子中with结构多数充当状语，表示行为方式，伴随情况、时间、原因或条件(详见上述例句)。
——45个基本介词的用法 1、about 【原始含义】 a-b-out “A在B外面” 【引申含义】 [prep] （1）在…到处，在…各处here and there eg: We wandered about the town for an hour or so. He looked about the room. （2）在…附近next to a place eg. She lives about the office. （3）关于in connection with eg: a book about English study I don’t know what you are talking about. [adv] （1）大约close to eg: We left there about 10 o’clock. It costs about 500 dollars. （2）到处，各处 eg: The children were rushing about in the garden. （3）在附近 eg : There is no food about. 【常见搭配】 作介词时的搭配: 一.动词+(about+名词) （1）arrange (about sth) 安排关于某事（2）argue (about sth) 讨论某事 （3）ask (about sth) 询问关于某事（4）boast (about sb/sth) 吹嘘... （5）care (about sb/sth)关心…,对…感兴趣（6）chat(about sth) 谈论某事（7）complain(about sb/sth) 抱怨… （8）dream (about sb/sth) 梦见某人/某物（9）go (about sth) 着手做...；从事...
with用法归纳 （1）“用……”表示使用工具，手段等。例如： ①We can walk with our legs and feet. 我们用腿脚行走。 ②He writes with a pencil. 他用铅笔写。 （2）“和……在一起”，表示伴随。例如： ①Can you go to a movie with me? 你能和我一起去看电影'>电影吗？ ②He often goes to the library with Jenny. 他常和詹妮一起去图书馆。 （3）“与……”。例如： I’d like to have a talk with you. 我很想和你说句话。 （4）“关于，对于”，表示一种关系或适应范围。例如： What’s wrong with your watch? 你的手表怎么了？ （5）“带有，具有”。例如： ①He’s a tall kid with short hair. 他是个长着一头短发的高个子小孩。 ②They have no money with them. 他们没带钱。 （6）“在……方面”。例如： Kate helps me with my English. 凯特帮我学英语。 （7）“随着，与……同时”。例如： With these words, he left the room. 说完这些话，他离开了房间。 [解题过程] with结构也称为with复合结构。是由with+复合宾语组成。常在句中做状语，表示谓语动作发生的伴随情况、时间、原因、方式等。其构成有下列几种情形： 1.with+名词(或代词)+现在分词 此时，现在分词和前面的名词或代词是逻辑上的主谓关系。 例如:1)With prices going up so fast, we can't afford luxuries. 由于物价上涨很快，我们买不起高档商品。（原因状语） 2)With the crowds cheering, they drove to the palace. 在人群的欢呼声中，他们驱车来到皇宫。（伴随情况） 2.with+名词(或代词)+过去分词 此时，过去分词和前面的名词或代词是逻辑上的动宾关系。
For的用法 1. 表示“当作、作为”。如: I like some bread and milk for breakfast. 我喜欢把面包和牛奶作为早餐。 What will we have for supper? 我们晚餐吃什么? 2. 表示理由或原因,意为“因为、由于”。如: Thank you for helping me with my English. 谢谢你帮我学习英语。 3. 表示动作的对象或接受者,意为“给……”、“对…… (而言)”。如: Let me pick it up for you. 让我为你捡起来。 Watching TV too much is bad for your health. 看电视太多有害于你的健康。 4. 表示时间、距离,意为“计、达”。如: I usually do the running for an hour in the morning. 我早晨通常跑步一小时。 We will stay there for two days. 我们将在那里逗留两天。 5. 表示去向、目的,意为“向、往、取、买”等。如: Let’s go for a walk. 我们出去散步吧。 I came here for my schoolbag.我来这儿取书包。 I paid twenty yuan for the dictionary. 我花了20元买这本词典。 6. 表示所属关系或用途,意为“为、适于……的”。如: It’s time for school. 到上学的时间了。 Here is a letter for you. 这儿有你的一封信。 7. 表示“支持、赞成”。如: Are you for this plan or against it? 你是支持还是反对这个计划? 8. 用于一些固定搭配中。如: Who are you waiting for? 你在等谁? For example, Mr Green is a kind teacher. 比如,格林先生是一位心地善良的老师。 尽管for 的用法较多，但记住常用的几个就可以了。 to的用法: 一：表示相对，针对 be strange (common, new, familiar, peculiar) to This injection will make you immune to infection. 二：表示对比，比较 1：以-ior结尾的形容词，后接介词to表示比较，如：superior ,inferior,prior,senior,junior 2: 一些本身就含有比较或比拟意思的形容词，如equal，similar，equivalent，analogous A is similar to B in many ways.
介词with的用法大全 With是个介词，基本的意思是“用”，但它也可以协助构成一个极为多采多姿的句型，在句子中起两种作用；副词与形容词。 with在下列结构中起副词作用： 1.“with+宾语+现在分词或短语”，如： (1) This article deals with common social ills, with particular attention being paid to vandalism. 2.“with+宾语+过去分词或短语”，如： (2) With different techniques used, different results can be obtained. (3) The TV mechanic entered the factory with tools carried in both hands. 3.“with+宾语+形容词或短语”，如： (4) With so much water vapour present in the room, some iron-made utensils have become rusty easily. (5) Every night, Helen sleeps with all the windows open. 4.“with+宾语＋介词短语”，如： (6) With the school badge on his shirt, he looks all the more serious. (7) With the security guard near the gate no bad character could do any thing illegal. 5.“with+宾语＋副词虚词”，如： (8) You cannot leave the machine there with electric power on. (9) How can you lock the door with your guests in? 上面五种“with”结构的副词功能，相当普遍，尤其是在科技英语中。 接着谈“with”结构的形容词功能，有下列五种： 一、“with+宾语+现在分词或短语”，如： (10) The body with a constant force acting on it. moves at constant pace. (11) Can you see the huge box with a long handle attaching to it ? 二、“with+宾语+过去分词或短语” (12) Throw away the container with its cover sealed. (13) Atoms with the outer layer filled with electrons do not form compounds. 三、“with+宾语+形容词或短语”，如： (14) Put the documents in the filing container with all the drawers open.
1.表示各种“目的”，用for （1）What do you study English for 你为什么要学英语？ （2）went to france for holiday. 她到法国度假去了。 （3）These books are written for pupils. 这些书是为学生些的。 （4）hope for the best, prepare for the worst. 作最好的打算，作最坏的准备。 2．“对于”用for （1）She has a liking for painting. 她爱好绘画。 （2）She had a natural gift for teaching. 她对教学有天赋/ 3．表示“赞成、同情”，用for （1）Are you for the idea or against it 你是支持还是反对这个想法？ （2）He expresses sympathy for the common people.. 他表现了对普通老百姓的同情。 （3）I felt deeply sorry for my friend who was very ill. 4. 表示“因为，由于”（常有较活译法），用for （1）Thank you for coming. 谢谢你来。
（2）France is famous for its wines. 法国因酒而出名。 5．当事人对某事的主观看法，“对于（某人），对…来说”，（多和形容词连用），用介词to，不用for. （1）He said that money was not important to him. 他说钱对他并不重要。 （2）To her it was rather unusual. 对她来说这是相当不寻常的。 （3）They are cruel to animals. 他们对动物很残忍。 6．和fit, good, bad, useful, suitable 等形容词连用，表示“适宜，适合”，用for。（1）Some training will make them fit for the job. 经过一段训练，他们会胜任这项工作的。 （2）Exercises are good for health. 锻炼有益于健康。 （3）Smoking and drinking are bad for health. 抽烟喝酒对健康有害。 （4）You are not suited for the kind of work you are doing. 7. 表示不定式逻辑上的主语，可以用在主语、表语、状语、定语中。 （1）It would be best for you to write to him. （2） The simple thing is for him to resign at once.
1.两者都可以引出间接宾语，但要根据不同的动词分别选用介词to 或for：(1) 在give, pass, hand, lend, send, tell, bring, show, pay, read, return, write, offer, teach, throw 等之后接介词to。 如： 请把那本字典递给我。 正：Please hand me that dictionary. 正：Please hand that dictionary to me. 她去年教我们的音乐。 正：She taught us music last year. 正：She taught music to us last year. (2) 在buy, make, get, order, cook, sing, fetch, play, find, paint, choose,prepare, spare 等之后用介词for 。如： 他为我们唱了首英语歌。 正：He sang us an English song. 正：He sang an English song for us. 请帮我把钥匙找到。 正：Please find me the keys. 正：Please find the keys for me. 能耽搁你几分钟吗(即你能为我抽出几分钟吗)? 正：Can you spare me a few minutes? 正：Can you spare a few minutes for me? 注：有的动词由于搭配和含义的不同，用介词to 或for 都是可能的。如：do sb a favour＝do a favour for sb 帮某人的忙 do sb harm＝do harm to sb 对某人有害
介词at的基本用法： 一、at引导的时间短语通常可表示： 1.在几点几分，例如：at one o’clock(在一点钟) I usually make the bed at one o’clock.. 2.在用餐时间，例如：at lunchtime（在午餐时间） 3.在某个节日，例如：at Christmas 在圣诞节的时候 4.在某个年龄的时候，例如：at the age of 12。在12岁的时候 5.一天中的某段较短的时间，例如：at noon在中午at night在夜里 二、at也可引导地点短语，常用于小地点之前，例如： at the bus stop在汽车站at the butcher’s 在肉店里at school在学校里at home在家里 介词on的基本用法： 一、on可引导地点短语，表示“在…上面”，例如：on the table在桌子上 二、on也可引导时间短语，通常有以下用法： 1.用于“星期”和“月份”中的任何一天之前，例如：On Monday在星期一on April 1st. 2.用于某个“星期几”当天的某段时间，例如：on Monday morning在星期一上午 3.用于具体某一天之前，例如：on that day在那一天On my birthday在我的生日那天 On Christmas day在圣诞节那天 介词in的基本用法： 一、in可引导地点短语，常表示“在…里面”，例如：in the bag在袋子里 二、in引导的时间短于通常有以下用法： 1.在某个世纪，例如：in the 21st century在21世纪 2.在某一年，例如：in 1995在1995年 3.在某一个季节，例如：in spring在春季 4.在某一个月份，例如：in March在三月里 5.在某段时期，例如：in the holidays在假期里 6.在某个持续几天的节日里，例如：in Easter Week在复活周 7.在一天中的某段时间，例如：in the morning在上午（早晨）
介词“with”的用法 1、同, 与, 和, 跟 talk with a friend 与朋友谈话 learn farming with an old peasant 跟老农学习种田 fight [quarrel, argue] with sb. 跟某人打架 [争吵, 辩论] [说明表示动作的词, 表示伴随]随着, 和...同时 change with the temperature 随着温度而变化 increase with years 逐年增加 be up with the dawn 黎明即起 W-these words he left the room. 他说完这些话便离开了房间。2 2、表示使用的工具, 手段 defend the motherland with one s life 用生命保卫祖国 dig with a pick 用镐挖掘 cut meat with a knife 用刀割肉3
3、说明名词, 表示事物的附属部分或所具有的性质]具有; 带有; 加上; 包括...在内 tea with sugar 加糖的茶水 a country with a long history 历史悠久的国家4 4、表示一致]在...一边, 与...一致; 拥护, 有利于 vote with sb. 投票赞成某人 with的复合结构作独立主格,表示伴随情况时，既可用分词的独立结构，也可用with的复合结构： with +名词(代词)+现在分词/过去分词/形容词/副词/不定式/介词短语。例如： He stood there, his hand raised. = He stood there, with his hand raise.他举手着站在那儿。 典型例题 The murderer was brought in, with his hands ___ behind his back A. being tied B. having tied C. to be tied D. tied 答案D. with +名词(代词)+分词+介词短语结构。当分词表示伴随状况时，其主语常常用
1. 两者都可以引出间接宾语，但要根据不同的动词分别选用介词to 或for： (1) 在give, pass, hand, lend, send, tell, bring, show, pay, read, return, write, offer, teach, throw 等之后接介词to。 如： 请把那本字典递给我。 正：Please hand me that dictionary. 正：Please hand that dictionary to me. 她去年教我们的音乐。 正：She taught us music last year. 正：She taught music to us last year. (2) 在buy, make, get, order, cook, sing, fetch, play, find, paint, choose,prepare, spare 等之后用介词for 。如： 他为我们唱了首英语歌。 正：He sang us an English song. 正：He sang an English song for us. 请帮我把钥匙找到。 正：Please find me the keys. 正：Please find the keys for me. 能耽搁你几分钟吗(即你能为我抽出几分钟吗)? 正：Can you spare me a few minutes? 正：Can you spare a few minutes for me? 注：有的动词由于搭配和含义的不同，用介词to 或for 都是可能的。如： do sb a favou r do a favour for sb 帮某人的忙 do sb harnn= do harm to sb 对某人有害
介词 介词不能单独作句子成分，而是用来表示名词或代词等和句中其他词的关系，通常放在名词或代词之前，构成介词短语。介词短语作为一个成分在句中可用作定语，表语，状语等。When shall we have the talk on the history of the Party我们何时听党史报告（定语）His elder brother is in the army.他的哥哥在部队。（表语） I went to school at half past seven yesterday.昨天我7：30 上学。（状语） 《 Will you please come along with me跟我一起走好吗（状语） ※同一个汉语词可以译成不同的英语介词。例如： 一幢石头的房子 a house of stone 这个房间的钥匙 the key to this room 明天的票 the ticket for tomorrow 《 （一）About 1．表示地点：在。。。周围；在。。。附近 We took the foreign guests about the campus. 我们带领外宾在校园里各处看看。 2．表示时间：大约。。。；近于。。。时刻前后We left there about six o’clock 我大约在六点左右离开那个地方。 3．表示客体关系：对于；关于；有关。例如：1) I must see him, I’ve heard so much about him 我必须要见他，我听到很多关于他的事情。2) What do you know about China 关于中国你知道些啥 （二）Above 表示位置，职位，数量，年龄等：在。。。上方；在。。。之上；超过。。。 1) Henry’s work is well above the average.亨利的功课大大超过一般水平。 2) A bird is flying above the woods. 一只鸟在树林上飞。 3) The portrait is above the blackboard.一幅肖像挂在黑板的上方。 4) It weighs above five tons. 这东西有5 吨多重。 （三）Across 1．表动作方向/位置：横过；穿过。（在表面）1）The boy helped the old lady across the street. 男孩扶老大娘穿过马路。2) The tree had fallen down across the railway line.树倒啦，横在铁路上。 2．表示地点：在对面；在。。。的另一边。 1）The church is across the river. 教堂在河的对面。 （四）After 1.表示时间或位置：在。。。之后。 1）Please line up one after another. 请一个挨一个排好对。 He goes on working day after day ,week after week without any change. 他继续日复一日地工作，没有丝毫改变。Shut the door after you. 随手关门！ 2．引伸意义：仿照；按照。 Please make sentences after the model. 请照示例造句。 ※（五）Against 1．表示位置：依着；紧靠；撞击；碰着。 1) He rested his bike against the wall.他把自行车靠在墙上。 2) The rain was beating against the windows. 雨敲打着窗户。 2．引伸意义：反对；禁止。 1）Are you for it or against it 你是赞成还是反对 2) Is there a law in this country against spitting right and left 你们国家有没有反对随地吐痰的规定
英语介词with的用法 with结构是许多英语复合结构中最常用的一种。学好它对学好复合宾语结构、不定式复合结构、动名词复合结构和独立主格结构均能起很重要的作用。本文就此的构成、特点及用法等作一较全面阐述，以帮助同学们掌握这一重要的语法知识。 一、 with结构的构成 它是由介词with或without+复合结构构成，复合结构作介词with或without的复合宾语，复合宾语中第一部分宾语由名词或代词充当，第二部分补足语由形容词、副词、介词短语、动词不定式或分词充当，分词可以是现在分词，也可以是过去分词。With结构构成方式如下： 1. with或without-名词/代词+形容词； 2. with或without-名词/代词+副词； 3. with或without-名词/代词+介词短语； 4. with或without-名词/代词+动词不定式； 5. with或without-名词/代词+分词。 下面分别举例： 1、 She came into the room，with her nose red because of cold.（with+名词+形容词，作伴随状语） 2、 With the meal over ， we all went home.（with+名词+副词，作时间状语） 3、The master was walking up and down with the ruler under his arm。（with+名词+介词短语，作伴随状语。） The teacher entered the classroom with a book in his hand. 4、He lay in the dark empty house，with not a man ，woman or child to say he was kind to me.（with+名词+不定式，作伴随状语） He could not finish it without me to help him.（without+代词 +不定式，作条件状语） 5、She fell asleep with the light burning.（with+名词+现在分词，作伴随状语） 6、Without anything left in the cupboard， she went out to get something to eat.（without+代词+过去分词，作为原因状语）
to和for的用法有什么不同（一） 一、引出间接宾语时的区别 两者都可以引出间接宾语，但要根据不同的动词分别选用介词to 或for，具体应注意以下三种情况： 1. 在give, pass, hand, lend, send, tell, bring, show, pay, read, return, write, offer, teach, throw 等之后接介词to。如： 请把那本字典递给我。 正：Please hand me that dictionary. 正：Please hand that dictionary to me. 她去年教我们的音乐。 正：She taught us music last year. 正：She taught music to us last year. 2. 在buy, make, get, order, cook, sing, fetch, play, find, paint, choose, prepare, spare 等之后用介词for 。如： 他为我们唱了首英语歌。 正：He sang us an English song. 正：He sang an English song for us. 请帮我把钥匙找到。 正：Please find me the keys. 正：Please find the keys for me. 能耽搁你几分钟吗(即你能为我抽出几分钟吗)? 正：Can you spare me a few minutes?
正：Can you spare a few minutes for me? 3. 有的动词由于用法和含义不同，用介词to 或for 都是可能的。如： do sb a favor＝do a favor for sb 帮某人的忙 do sb harm＝do harm to sb 对某人有害 在有的情况下，可能既不用for 也不用to，而用其他的介词。如： play sb a trick＝play a trick on sb 作弄某人 请比较： play sb some folk songs＝play some folk songs for sb 给某人演奏民歌 有时同一个动词，由于用法不同，所搭配的介词也可能不同，如leave sbsth 这一结构，若表示一般意义的为某人留下某物，则用介词for 引出间接宾语，即说leave sth for sb；若表示某人死后遗留下某物，则用介词to 引出间接宾语，即说leave sth to sb。如： Would you like to leave him a message? / Would you like to leave a message for him? 你要不要给他留个话？ Her father left her a large fortune. / Her father left a large fortune to her. 她父亲死后给她留下了一大笔财产。 二、表示目标或方向的区别 两者均可表示目标、目的地、方向等，此时也要根据不同动词分别对待。如： 1. 在come, go, walk, move, fly, ride, drive, march, return 等动词之后通常用介词to 表示目标或目的地。如： He has gone to Shanghai. 他到上海去了。 They walked to a river. 他们走到一条河边。