that引導的主語從句
(一)
當主語從句本身不缺成分時,就會使用that來連線。此時,that只起連線作用,但不能省略。如:
That he will come to our village tomorrow surprises us all. (他要來我們村,讓我們都感到很驚訝。)That she used to be a spy is known to all. (大家都知道,她過去是個間諜。)
這種情況下,因為主語從句往往比謂語部分更長,會導致整個句子頭重腳輕,所以經常會用it作為形式主語來替換主語從句,而把主語從句放到句末。此時,that也只起連線作用,但可以省略。比如,以上兩個句子就存在這個問題,所以一般都會改為:
It surprises us all (that) he will come to our village tomorrow.It is known to all (that) she used to be a spy.
(二)
如果句子是疑問句,則必須用帶形式主語it的結構。如:
That she is our English teacher is true. (她是我們的英語老師,是真的。)That he has been there twice is a fact. (他去過那兒兩次了,是真的。)
這兩句話如果改為一般疑問句時,不能這麼改:
錯誤:Is that she is your English teacher true?錯誤:Is that he has been there twice a fact?
而是要改為含有形式主語it的句子:
Is it true that she is your English teacher?Is it a fact that he has been there twice?
(三)
在形式主語it引導的主語從句結構“It is+形容詞/名詞/名詞短語等+that主語從句”中,如果is後面的表語是表示重要或必要等(如important、necessary、a necessity等)含義時,that從句中的謂語動詞一般要採用“should+do”的虛擬語氣形式,should經常省略。如:
It is imperative that we (should) make a quick decision. (我們要儘快做出決定。)It is necessary that we (should) learn English well. (我們必須學好英語。)
that引導的主語從句
(一)
當主語從句本身不缺成分時,就會使用that來連線。此時,that只起連線作用,但不能省略。如:
That he will come to our village tomorrow surprises us all. (他要來我們村,讓我們都感到很驚訝。)That she used to be a spy is known to all. (大家都知道,她過去是個間諜。)
這種情況下,因為主語從句往往比謂語部分更長,會導致整個句子頭重腳輕,所以經常會用it作為形式主語來替換主語從句,而把主語從句放到句末。此時,that也只起連線作用,但可以省略。比如,以上兩個句子就存在這個問題,所以一般都會改為:
It surprises us all (that) he will come to our village tomorrow.It is known to all (that) she used to be a spy.
(二)
如果句子是疑問句,則必須用帶形式主語it的結構。如:
That she is our English teacher is true. (她是我們的英語老師,是真的。)That he has been there twice is a fact. (他去過那兒兩次了,是真的。)
這兩句話如果改為一般疑問句時,不能這麼改:
錯誤:Is that she is your English teacher true?錯誤:Is that he has been there twice a fact?
而是要改為含有形式主語it的句子:
Is it true that she is your English teacher?Is it a fact that he has been there twice?
(三)
在形式主語it引導的主語從句結構“It is+形容詞/名詞/名詞短語等+that主語從句”中,如果is後面的表語是表示重要或必要等(如important、necessary、a necessity等)含義時,that從句中的謂語動詞一般要採用“should+do”的虛擬語氣形式,should經常省略。如:
It is imperative that we (should) make a quick decision. (我們要儘快做出決定。)It is necessary that we (should) learn English well. (我們必須學好英語。)