新人教版八年级下册英语 unit 8单元语法小专题(Grammar Focus)

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单元语法小专题(Grammar Focus)

语法精讲

现在完成时(一)

1.现在完成时的构成

现在完成时由“have/has+过去分词”构成。其中have/has是助动词,has用于第三人称单数;规则动词过去分词的构成与其过去式相同,不规则动词的过去分词需加强记忆(详见课本后面的附表)。

(1)含有现在完成时的肯定句变为否定句时,应直接在have或has后面加not,have not常简略为 haven't,has not常简略为hasn't。如:

They haven't seen the film before.他们以前没有看过这部电影。

It's time for class.but Linda hasn't arrived.该上课了,但是琳达还没有到。

(2)含有现在完成时的肯定句变为一般疑问句时,应将have或has提到句首,对其进行肯定回答时,常用“Yes,主语+have/has.”;对其进行否定回答时,常用“No,主语+haven't/hasn't.”或“Not yet.”等。如:

—Have you found your lost bike yet? 你找到你丢失的自行车了吗?

—Yes.I have./No,I haven't.是的,我找到了。/不,我还没有找到。

现在完成时的不同句式结构如下图:

2.现在完成时的用法

(1)表示过去发生或已经完成的动作对现在造成的影响或结果。此时句中可不用任何时间状语,也可与表示不确定时间的副词already,just,ever,never,yet,recently等连用。如:

I have never seen such beautiful pictures before.我以前从未见过这么漂亮的图片。

The children's parents have just come back from work.孩子们的父母刚下班回来。

【注意】already强调某事已经发生,或者某种情况已经开始存在,多用于肯定句中;yet强调某事尚未发生,或者询问某事是否已经发生,多用于疑问句或否定句中。如:

Mom has already prepared for supper.妈妈已经准备好晚餐了。

Lily hasn't come back yet.莉莉还没有回来。

Haven't you got ready yet? 你还没准备好吗?

(2)表示从过去某一时间开始一直持续到现在的动作或状态。常与“since+时间点”“for+时间段”以及so far,in the past two years等时间状语连用。如:

It has been fine for weeks.天晴了好几个星期。

They have known each other since they were children.他们从小就认识。

We have planted more than 5,000 trees in the past three years.过去三年我们种了5000多棵树了。语法精练

01 基础训练

Ⅰ.用括号内所给单词的适当形式填空。

1.—Mom,may I go out to play football?

—Have you finished(finish) your homework yet? 2.—Do you know which city Jack is in?

—Sorry,I don't know.I haven't__heard(not hear) from him yet.

3.I can't go to the concert because I have__lost(lose) my ticket.

4.Uncle Li can speak English well because he has__been(be) in America for ten years.

5.My mother has__cleaned(clean) the windows already, so the room looks much brighter.

02 中考链接

(D)6.(2018·上海)The film Operation Red Sea ________ a lot of praise since its first show

months ago.

A.wins B.win

C.will win D.has won

(D)7.(2018·河北)I ________ an invitation to the concert.I can't wait to go.

A.receive B.will receive

C.was receiving D.have received

(C)8.(2018·福建)China ________great achievements in science and technology since 1978.

A.makes B.made

C.has made

(D)9.(2018·盐城)—I ________ my card.I want to report it.

—You can call the bank to report the loss.It would be faster.

A.lose B.was losing

C.will lose D.have lost