有时候, 条件从句表示的动作和主句表示的动作, 发生的时间是不一致的(如一个是过去发生的, 一个是现在发生的). 这时, 动词的形式要根据表示的时间来调整. 这种句子可以称为错综时间条件句.

If he had received six more votes, he would be our chairman now.

If we hadn't got everything ready by now, we should be having a terrible time tomorrow.

有时假设的情况并不以条件从句表示, 而是通过一个介词短语来表示.

Without music, the world would be a dull place.

We could have done better under more favorable conditions.

That would have been considered miraculous in the past.

But for the storm, we should have arrived earlier.

如果条件句从句中包含有 were, had, should 或could, 有时可把if省略掉, 并把were, had, should或could放在主语前面.

Had we made adequate preparation, we might have succeeded.

Should there be a flood, what should we do?

Were it not for their assistance, we would be in serious difficulty.

Ⅳ 介词

合成介词和复杂介词

合成介词: inside, into, onto, out of, outside, throughout, upon within, without

复杂介词: according to, along with, apart from, as for, as to, because of, by means of, in front of, in spite of, instead of, in accordance with, on account of, on behalf of, owing to, due to, together with, up to, with regard to, prior to等

介词在句末:

This is what he is interested in.

Does everyone has a seat to sit on?

名词加介词 ( n + prep)

某些名词之后要求用某些介词: solution to, faith in, glance at, need for

某些名词之前要求用某些介词: on one’s guard, at one’s request, in all probability, to my delight

动词加介词

Vi + prep: prevail on, appeal to, fall into, apply for, touch upon

Vt + O + prep: lay emphasis on, take advantage of等

Vi + adv + prep:

I don't wish to break in on your thoughts.

The family came up against fresh problems.

You're not telling me the whole story. You're holding out on me.

She got off with him soon after she began to work at the institution.

Vt + O + adv +prep:

You shouldn't take your resentment out on me.

We shouldn't put the shortage down to bad planning.

形容词加介词

about --- anxious, careful, careless, certain, considerate, enthusiastic, guilty, happy, mad, particular, sad, sure, timid, unhappy, etc

at --- awkward, bad, clever, disappointed, disgusted, good, marvellous, quick, skilful, skilled, useless, weak, etc

for --- convenient, eligible, grateful, homesick, hungry, necessary, noted, perfect, responsible, etc

from --- evident, exempt, inseparable, safe, tired, etc

in --- deficient, expert, liberal, quick, rich, successful, weak, etc

of --- apprehensive, characteristic, critical, destructive, envious, hard, inconsiderate, impatient, dependent, jealous,

positive, scared, sensible, short, sick, suspicious, typical, worthy, etc

on --- dependent, keen, intent, etc

to --- acceptable, accessible, agreeable, alive, attentive, blind, comparable, courteous, deaf, destructive, essential, favourable, hostile, indifferent, married, obedient, parallel, preferable, related, responsible, sensitive, suitable, unjust, etc

with --- awkward, bored, careful, disappointed, generous, identical, ill, impatient, popular, sick, wrong, etc