1. but作為關(guān)系代詞常與具有否定或疑問意義的主句連用,其引導(dǎo)的從句修飾的先行詞多是否定意義的,but=who ... not/which ... not/that ... not,意為“無不/沒有不/誰不”。
There's no one but knows the importance of English.
沒有不懂得英語重要性的人。
Not a single room in this hotel but is empty.
這個賓館沒有一個房間不是空的。
2. who ... but(=that ... not)意為“誰不……的?”
Who is there but makes some mistakes?
Who is there that does not make any mistakes?
人哪有不犯錯誤的?
3. what引導(dǎo)定語從句時既可指人也可指物,指人時what=the person(s) that,指物時what=the thing/all/everything that。
That is exactly what he told me.
that is exactly The thing he told me.
那正是他告訴我的。
4. what本身的作用已經(jīng)包含有先行詞和關(guān)系代詞。有一身兼兩職的作用,分別在主句和從句中作相應(yīng)的成分。
Don't do what you shouldn't do.
不要做你不應(yīng)該做的事。
Never pretend to know what you really don't know.
不要假裝知道你并非真正知道的事情。
5. 用what時,前無先行詞;若有先行詞,應(yīng)視其情況選擇使用that, which,或who。
What can be done has been done.
能做的都已經(jīng)做了。
All that can be sold has been sold.
所有能賣的都已經(jīng)賣了。
I have known everything that you want to tell me.
我已經(jīng)知道了你想告訴我的一切。
專項練習
1. Generally speaking, there is no one _______ loves their parents in the world.
A. that
B. but
C. who
D. A or B or C
2. All _______ is needed is a supply of oil.
A. the thing
B. that
C. what
D. which
3. _______ is over is over.
A. What
B. That
C. What all
D. All what
4. _______ were once truth are true no longer.
A. What
B. That
C. Which
D. All
5. _______ you have done might do harm to other people.
A. That
B. What
C. Which
D. This
6. A computer can only do _______ you have instructed it to do.
A. how
B. after
C. what
D. whom
7. They want to know _______ do to help us.
A. what can they
B. what they can
C. how they can
D. how can they
8. This is the longest train _______ I have ever seen.
A. which
B. that
C. what
D. whom
9. Who studies here _______ wants to go to college?
A. that
B. but
C. who
D. whom
10. There's none of us _______ wishes to go to Tsinghua University.
A. but
B. that
C. who
D. which
答案速查 1-5 BBAAB 6—10 CBBBA