高中英語語法重點難點回顧(3)

注意：不定式動詞在介詞but, except, besides后面時,如果這些介詞之前有行為動詞do的各種形式,那么,這些介詞后的不定式不帶to,否則要帶to.如：

She could do nothing but cry.

What do you like to do besides swim?

I have no choice but to go.

作定語的不定式如果是不及物動詞,或者不定式所修飾的名詞或代詞是不定式動作的地點、工具等,不定式后面須有相應(yīng)的介詞。例如：He is looking for a room to live in.

There is nothing to worry about.

Please give me a knife to cut with.

There / It is no use/ good/ not any use/ good/ useless doing sth.

動詞后可以用動名詞作賓語,但不能用不定式:

admit,appreciate, avoid, consider, delay, enjoy, escape, excuse, feel like, finish, forgive, give up, imagine, include, keep, mention,mind,miss,practise, put off, resist, risk, suggest, can't help, can't stand(無法忍受)等。

I tried not to go there.(我設(shè)法不去那里。)

I tried doing it again.(我試著又干了一次。)]

mean to do 有意... mean doing意味著...

I mean to come early today.(我打算今天早些來。)

Missing the train means waiting for another hour.

(誤了這趟火車意味著再等一個小時。)

allow, advise, forbid, permit

We don't allow smoking here. We don't allow students to smoke.

動詞need,require,want作“需要”解,其后跟動詞作它的賓語時,若表示的含義是被動的,必須用動名詞,或不定式的被動式。例如：

The window needs(requires, wants)cleaning(to be cleaned).

在短語devote to, look forward to, pay attention to, stick to, be used to, object to,thank you for, excuse me for 等后的動詞也必須用動名詞形式：I look forward to hearing from you soon.

Badly polluted, the water cannot be drunk.(原因)

Being written in haste, the composition is full of mistakes.

(原因,強調(diào)寫的過程,故應(yīng)用現(xiàn)在分詞一般被動式)

Having been deserted by his guide, he couldn't find his way through the jungle.(為了強調(diào)已完成的動作)

Asked to stay, I couldn't very well refuse.

這里 asked 可能意味著 having been asked, 也可能意味著when/since I was asked, 但用了 having been asked 就不會有歧義。

下面句中過去分詞表示的時間與謂語動詞所表示的時間相同，所以不能代之以強調(diào)先于謂語動詞的現(xiàn)在分詞完成被動式。例如：

Covered with confusion, I left the room.我很窘地離開了房間。

United, we stand; divided, we fall. 團結(jié)則存，分裂則亡。

He used to live in London, use(d)n't he /didn't he?

There used to be a cinema here before the war, use(d)n't there /didn't there?

Such things ought not to be allowed, ought they?

He ought to be punished, oughtn't he?

但在正式文體中,用ought we not形式。例如:

We ought to go, ought we not?或We ought to go ,should we not?

含有情態(tài)動詞must的句子表示推則,作“想必”解時,疑問部分不可用mustn't。若前句強調(diào)對現(xiàn)在情況的推測,疑問部分用aren't(isn't)十主語,例如：You must be tired,aren't you?若陳述部分的must表示“有必要”時,附加疑問句部分則用needn't。例如：You must go home right now, needn't you?

當(dāng)mustn't 表示禁止時,附加疑問部分一般用must。如：

You mustn't walk on grass, must you?

前句謂語動詞是must have＋過去分詞時,若前句強調(diào)對過去情況的推測(一般有過去時間狀語),疑問部分的謂語動詞用didn't＋主語;若前句強調(diào)動作的完成,疑問部分的謂語動詞用haven't(hasn't)＋主語, 例如：

He must have met her yesterday, didn't he?

You must have seen the film, haven't you?

陳述句謂語部分出現(xiàn)否定詞綴時(前綴或后綴),疑問部分仍用否定結(jié)構(gòu)。例如:He is unfit for his office, isn't he?

如果陳述部分包含有no, never, hardly, seldom, few, little,nowhere, nothing等否定或半否定詞時,疑問部分用肯定形式。例如：He is hardly 14 years old,is he?

如果陳述部分的主語為everyone,someone,no one等不定代詞,其疑問部分的主語可用he,也可用they。

Everyone knows his job, doesn't he?

Everyone knows their job,don't they?

No one was hurt,were they?

I'm late, aren't I?

One can't be too careful,can one(you)?

Have a cup of tea, will you?

Let's go there,shall we? Let us go there,will you?

同位語從句跟在名詞后面,進一步說明該名詞的具體內(nèi)容。引導(dǎo)同位語從句的名詞主要有fact, news, promise, idea, truth等。連接詞用that (不用which)及連接副詞how, when, where, why等。例如：

His delay is due to the fact that the car went wrong halfway.

The news that our team has won the match is true.

She asked the reason why there was a delay.