《英语学科知识》：英语必知18条重点语法（十五）

在that引导的宾语从句中，通常可省略第一个宾语从句的引导词that，其余的不能省。

1.The girls told him (that) they were on a train trip across Canada and that they had only one day in Montreal.

2.I’m sure (that) you will win the game.

在which, when, where, how, why引导的宾语从句中，常可省略与主语相同的部分，仅保留一个连接词。

1.My teacher will go to London, but I don’t know when (he will go to London).

2.She can’t come, but I don’t know why (she can’t come).

在对话中，答语有时是一个包含宾语从句的复合句，但常常省略从句。

1.—Will it snow tonight?

—I hope (it will) not (snow tonight).

2.—Is Mr. King in his office?

—Sorry, I don’t know(whether he is in his office or not).

定语从句中，作宾语的关系代词一般可省略。

She is the one (whom) we saw the other day.

在非正式文体的定语从句中，关系代词as后面的主谓成分或助动词be也可省略。

She gave the same answer as (she had given) before.

有些表示条件、时间、地点、方式或让步等的状语从句，如果谓语含有be动词，主语又和主句中的主语一致，或主语是it，常把从句中的主语和be动词省略。

1.If so (=If it is so), why has one of the earliest and greatest works in Western storytelling, Homer’s The Odyssey, never had an equally great movie based on it?

2.So what is the difference between them, if any (=if there is any difference between them)?

3.Look out for cars when crossing the street (=when you are crossing the street).

4.She hurriedly left the room as though/if angry(=as though/if she was/were angry).

5.As a young man (=As he was a young man), he studied law and become a lawyer.

6.She advised me not to say anything unless asked (=unless I was asked).

在以than或as引导的状语从句中，一些成分常可省略或用do进行替代省略。

1.There is more salt in it than (there is) sugar (in it).

2.You’d like it as soon as (it is) possible.

3.I don’t want to set down a series of facts in a diary as most people do (=set down a series of facts).

If引导的非真实条件句中含有were, had, should时，可将if省略，并倒装。

1.Were I you (=If I were you), I wouldn’t go with him.

2.Had Thomas Edison, the great inventor stored his money (=If Thomas Edison, the great inventor had stored his money), he would have died a wealthy man.