1．One作代词的用法
213 One 只能用作可数名词，可用来表示一个人、一棵树、一盏灯等等，不能指水、空气、羡慕、勇气等。
214 One可泛指“一个人”：
One（=A person）must obey one's（美国用法his）parents．
One always thinks oneself（美国用法himself）wise．
（比较：Everyone thinks himself wise[不可说oneself wise]．No－one thinks himself foolish [不可说oneself fool－ish]．）
One还可有一个定语短语或从句修饰它：
He is one（=a person）true to everybody．
One in a good humour pleases people about him．
You cannot dissuade one charmed by a woman．
He is not one to tell lies．
One who loves others loves himself．
间或后面可跟一个形容词：
He lay there like one dead（or mad，possessed）．
偶有下面用法：
He is one（=a rare sort of man）．
在表示人时，one不能用于复数形式。
215 有时one可用来代表刚刚提到的一种人，或这种人中的一个：
If there is any saint，I have seen one（＝a saint）．
Your brother is not a miser，but you are one（=a miser）．
也可指物，表示其中的一个：
There are houses for sale，and you can buy one（＝one house，not houses）．
You have no dictionary？I can lend you one．
不能代表复数的人或物，这时需用some代替：
If there are any saints，I have seen some（=some saints）．（泛指的one的复数形式为some）
There are houses for sale，and you can buy some．
216 和其他指示词不同，one和ones前面可加形容词，这时one（s）可称为替代词（Prop-Word）。这样用时，可读作[+n]和[+uz]：
A good book is different from a bad one（=a bad book）．
An honest businessman fares better than a cunning one（=acunning businessman）．
Honest businessmen fare better than cunning ones．
（作替代词时不用some，而用ones表示复数）
但在替代词ones前可加some：
Here are apples．You can take a ripe one（or some ripe ones）．
它只能用来代替可数名词，有时可有多种说法：
Is this an apple？I have never seen such a one（or so large aone）．
We should adopt a wise policy instead of a foolish policy．（普通说法）
We should adopt a wise policy instead of a foolish one．（口语中用法）
We should adopt a wise instead of a foolish policy．（书面语用法）
I prefer red roses to white（书面语）或to white ones．（口语体）
He has good books and bad（ones）或a good（book）and a badbook．
Wooden houses are not so strong as stone ones．（one也用在作定语的名词后面）
My house is a four-story one．
She is a pretty girl，and a country one．
I like all novels，especially nineteen-century ones．
但不能用来代替不可数名词：
I drink red wine and white（wine）．（不能说white
one）
He calls on me in fair weather or foul（weather）．（不能说foul one）
You can judge his public conduct by his private（conduct）．
I like black tea and green．
下面词组有其特别的意思：
Your little ones（=children）．My dear one（=darling）．
The Holy One（=God）．The Evil One（=The Devil）．
217 One前面可加形容词，却不能加名词所有格，或加某些指示词。下面的说法都是错误的：
my friend's one，my（own）one，either one，neither one；bothones，all ones，five ones
但可说：my friend's，or my friend's large one；mine，or myown，or my（own）large one；either，or either large one，ei-ther long one，either wounded one
也可说：each（one），another（one），any（one），the third（one），which（one or ones），whatever（one or ones），this（one），that（one），these（ones），those（ones）
218 和其他指示词一样，one和ones也可跟各种定语：
A good book is one（=a book）for the benefit of its readers（one written in blood and tears，one which pleases andteaches）．
After the death of his servant，he employed one（=a servant）skillful in cooking，recommended by Lee．
His faults are mainly ones（=faults）of negligence．
These five years are ones（=years）of political unrest．
219 One前可加the，表示一个特定的人或东西（即“那一个……”）：
I have five brothers．The one（=The brother）in China is the eldest．
“Which car do you like best？”“The one on the left side．”“The one lying by the tree．”“The one you see．”
I drew my chair to the one（=the chair）in which my uncle was sitting．
My house is near to the one belonging to Major Wang．
Of all jobs，I like the ones（=the jobs）done for the benefit of children．
Good students are always the ones（=the students）working hard．
注：the one和the ones是口语中的用法，在书面语中可用that和those代替。
220 在用one作主语时，要注意动词用哪种形式：
One of the greatest rivers in the world is（不是are）the Yang-tze．
He is one of the best engineers that are（不是is）working in this factory．
He is one of the best engineers，who is（不是are）expert in building bridges．（who前有逗号，这时指的是one而不是指engineers。）
They are some of（不能说ones of）the best engineers I know．
They are among（=some of）the best engineers I know．
221 由one构成的代词都是单数：
Someone is coming．（某一个人）
No one knows it．No one of them can do it．（两者重音不同）
Anyone can make it．
Everyone seems happy．
Some one of us is absent today．（指某一个人）
Some one of the chairs is too old．
None of these is（or are）interesting．
Every one of those lawyers is rich．
Any one of the stree
ts is dirty．
2．One作形容词的用法
222 One常可与一名词连用，表示时间，这时常不加介词：I saw him one morning（or afternoon，evening）．（但：I saw him on a spring morning，on a July evening．）
I saw him one day．
I shall see him some（or one）day．
有时可用在人名前表示“某一个”：
I was introduced to one Doctor Johnson．
I met one Mr．Lee（or a Mr．Lee）（=a certain person）．