常見的強調句結構是it 引導的句子。
It is (was) 被強調部分+ that (who) + 句子其他部分。
此結構強調的成分僅限于主語，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.
使用此句型時, 應注意以下幾點。
(1) 一般情況用It is(was)……that…如:
He read three books in the library yesterday.
我們分別可以強調主語、賓語、地點狀語和時間狀語。如:
It was he who(that)read three books in the library yesterday. (強調主語)
It was three books that he read in the library yesterday. (強調賓語)
It was in the library that he read three books yesterday. (強調時間狀語)
(2) 當被強調部分指人時, 可用that, 也可用who; 指物時, 只用that, 如:
It was Tom who(that)I met last week.
It is a new boke that his brother wants to buy.