①构成和判断：
“It is/was＋被强调的部分(时间状语/地点状语/原因状语/方式状语/名词/代词/从句)＋that(指人可用who)＋句子的其余部分”。如：
It was because he was ill that he was absent.
②一般疑问句和特殊疑问句的强调句。如：
Was_it on the street that_you met Tom?
What_was_it_that made him upset?
Do you know what_it_was_that_made_him_upset?
[注]强调句型用于宾语从句时应用陈述语序。
③not until的强调句，其结构为“It is/was not until＋被强调部分＋that＋句子剩余部分”。如：
It was not until I came back that he left.
④强调谓语用“does/do/did＋动词原形”。如：
He did come back yesterday.
