在大學英語四級考試中，單獨考察英語四級語法的題幾乎沒有，但是英語四級語法知識點卻貫穿整張試卷，下面是英語四級頻道為大家整理的大學英語四級語法知識，希望可以為大家?guī)韼椭?，預祝大家考試順利過關。
2019年12月大學英語四級語法大全目錄
13.3 強調(diào)句結構
?？嫉膹娬{(diào)句結構是it 引導的句子。
It is (was) 被強調(diào)部分+ that (who) + 句子其他部分。
此結構強調(diào)的成分僅限于主語，賓語和狀語。
It is from the sun that we get light and heat.
It was not until I had read your letter that I understood the true state of affairs.
典型例題
1) It was last night ___ I see the comet.
A. the time B. when C. that D. which
答案C. 強調(diào)句的結構是： It +be +強調(diào)部分 + that (who) + 主謂句?！娬{(diào)句的連詞只有兩個，that和who。當強調(diào)的部分是人，且為句子的主語時，才用 "who"，其余用that。
原句： My father did the experiment in the lab yesterday evening.
強調(diào)主語： It was my father who did the experiment in the lab yesterday evening.
強調(diào)賓語： It was the experiment that my father did in the lab yesterday evening.
強調(diào)時間： It was yesterday evening that my father did the experiment in the lab. (注意不用when)
強調(diào)地點： It was in the lab that my father did the experiment yesterday evening.
2)It is ten years ___ Miss Green returned to Canada.
A. that B. when C. since D. as
答案C. 考點是連詞用法。 本題易誤選為A. that. 其實本句不是強調(diào)句。若是，去掉It be… that還應是一個完整的句子。而本句去掉 'It is…that'，只剩下ten years Miss Green returned to Canada. 不成句。因此本句不是強調(diào)句。
It is /was +時間+ since… 其中is<---> has been was <---> had been.