发布时间:2022-05-11T22:55:04 英语语法




一、if + 形容词


Send the goods now if ready.= Send the goods now if they are ready. 货物如已备好,请即送来。

If true, this will cause us a lot of trouble.= If it is true, this will cause us a lot of trouble. 这事若是事实,它将给我们造成许多麻烦。

注:这类省略结构中有的已构成相对固定的搭配,if necessary (如果需要),if possible (如果可能)等。如:

If necessary, ring me at home. 如果必要,可往我家里打电话。

If possible, let me know beforehand. 如果可能,可在事前通知我。

二、if + 过去分词


He will come if asked.= He will come if he is asked. 他如被邀就会来。

The medicine is quite effective if taken in time.=The medicine is quite effective if it is taken in time. 这药要是能按时服用,效果是很好的。

三、if + 代词


If anyone, he knows. 如果有人知道,那就是他了。

There are few people nowadays, if any, who remember him. 当今记得他的人,如有的话,也不多了。

He seems to have little, if anything, to do with this. 若要说他和这事有什么相关的话,那也似乎是很少的。

四、if + 介词短语

这类结构往往要根据具体的语境来理解,但有些经常搭配的惯用结构也值得注意,如if in doubt, if at all, if by any chance等。如:

If in doubt, ask your doctor. He can give you further information. 你若有疑问,可以问问医生. 他会向你作进一步的说明。

Their policies have changed little, if at all, since the last election. 自上次选举以来,他们的政策就算是有所变化,也变得很少。

If by any chance you can’t manage dinner tonight, perhaps we can at least have a drink together. 就算你今晚不吃晚饭,也许我们至少可以一起喝一杯。

五、if + ever

if ever 可视为习语,它通常与seldom连用,表示“极少”“难得”。如:

She seldom, if ever, goes to the cinema. 她难得看电影。

He seldom if ever travels abroad. 他到国外旅行,即使有过,也是极少的。


The island is seldom if ever visited by ships. 这个岛难得有船停靠。


If ever you’re in Cambridge, do give me a ring. 万一你来剑桥,一定要给我打电话。

六、if + not

if not 可视为一个否定的条件状语从句省略。如:

I might see you tomorrow. If not, then it’ll be Saturday. 我可能明天去看你。如果不是明天,那就在周六。

Ask her if it is a convenient time. If not, can she suggest another possible time? 问问她那个时间方便不方便。要是不方便,那她可不可以提出一个可行的时间­?


If not today, tomorrow I’m sure you’ll get an answer. 如果今天得不到回信,明天准能得到。

This is one of the oldest buildings in town, if not the oldest. 这是城里最古老的房屋之一,如果不是最古老的话。

Usually, if not always, we write “cannot” as one word. 我们即使不总是如此,也通常是把cannot作为一个词来拼写的。

七、if + so

if so的意思是“如果是那样的话”。如:

I may be free this evening. If so, I’ll come round and see you. 今晚我可能有空。要是有空我会过来看你。

They must decide if such a plan can be implemented and if so, when. 他必须决定这样的计划是否能实施,而且要是能实施的话,又得决定何时实施。

注意以下if so与if not连用的情形:

He may be busy. If so, I’ll call later. If not, can I see him now? 他可能忙,如是这样,我以后再来拜访。他如不忙,我现在可以见他吗?

Will you be staying another night? If so, we can give you a better room. If not, could you be out of your room by 12:00? 您要再往一晚吗? 如果是这样,我们可以给您提供条件更好一点的房间。如果不是,您能在12点前离开这房间吗?

八、if need be 如果需要

if need be为习语,其含义相当于if it is necessary (如果有必要的话)。如:

I will come if need be. 如有必要我会来。

I’ll work at night if need be. 如果有必要我可以晚上工作。

If need be we can always bring another car. 如果有必要的话我们还可以再开一辆车来。