1. 通常要用which的場合:
①引導非限制性定語從句時,通常只用which。如:
Water, which is a clear liquid, has many uses. 水是一種清澈的液體,有許多用途。
which在此引導的是非限制性定語從句,故不可換成that。
?、谥苯臃旁诮樵~后作賓語時,通常只用which。如:
I admired the patience with which she spoke. 她說話有極大的耐心,我很欽佩。
直接用作介詞with之后作賓語,只能用which,不能用that。
2. 通常要用that的場合:
?、佼斚刃性~是much, little, none, all, few, every(thing), any(thing), no(thing) 等不定代詞或受其修飾時,通常用that。如:
We haven’t got everything that you ordered. 你要的,我們不是樣樣都有。
All that remains for me to do is to say goodbye. 剩下我所要做的就是告辭了。
第一句中的定語從句that you ordered修飾不定代詞everything,第二句中的定語從句that remains for me to do修飾不定代詞all。兩個定語從句中的that都不宜換成which。
?、诋斚刃性~受the very, the only, the same 等修飾時,通常用that。如:
This is the only example that I know. 我知道的例子只有這一個。
Those are the very words that he used. 那是他的原話。
受定語從句修飾的example和words前分別有the only和the very修飾,故要定語從句要用that來引導。另外注意,第二句中的the very不是表示“很”,而是表示“正是”“恰是”,very在此為形容詞,而不是副詞。
?、郛斚刃性~有形容詞最高級或序數(shù)詞(包括last, next等)等修飾時,通常用that。如:
This is the best hotel that I know. 這是我知道的最佳旅館。
The first thing that you should do is to work out a plan. 你應(yīng)該做的第一件事是訂個計劃。
?、墚旉P(guān)系代詞在定語從句中用作表語時,通常用that。如:
China is not the country (that) it was. 中國已不是過去的樣子了。
that it was為修飾名詞the country的定語從句,that在定語從句中用作連系動詞was的表語,此時可以省略,但不宜換成which。
?、莓斚刃性~是一個既指人又指物的并列詞組時,通常用that。如:
The train ran over a boy and his dog that were just crossing the track. 火車壓死了正穿越軌道的一個男孩和他的狗。
定語從句that were just crossing the track修飾的不只是his dog,而是a boy and his dog,由于它既包含有人也包含物,故用that。
?、蕻斠苊庵貜蜁r。如:
Which is the car that overtook us? 超過我們的是哪輛車?
由于句首用了which,所以后面修飾the car的定語從句that overtook us要用that來引導,而不用which,目的是為了避免與句首which的重復。