1.强调句形式1：
强调的部分为主语，宾语，状语
It is/was___A___that____B_____
是…
A+B=一个完整的句子，这就是个强调句。
replace，exchange，substitute
replace A with B 用B去代替A
exchange A for B 用A去交换B
substitute A for B 用A替换B
例题
I saw him on the street last night
强调主语,当强调主语是人的时候，可以用who
It was I that/who saw him on the street last night. 强调宾语
It was him that/who I saw on the street last night. 强调状语
It was on the street that saw him last night.
1.1.强调句的疑问形式
It is __A__that……
疑问词(what)+is it that……
区分：
It is required in the regulation that you should not tell other
A
people the password of your e-mail account.
B
这里的It 是形式主语，真正的主语是you should not tell other people the password of your e-mail account.
区分原理：把It is……that 去掉后看A+B合起来是否是完整的句子，此句子很明显不是完整的句子。
2.强调句形式2：
not…until +句子直到…才
It was not until 句子+that + 剩余部分
Mary didn’t leave the office until it was dark.
这就是until+句子
变为强调句：
It was not until it was dark that mary leaf the office.
直到天黑，mary才离开办公室。
例：
Americas didn’t realize the severity of the situation until the subprime loan had caused great damage to the financial system. 直到次级贷款对金融系统造成巨大破坏，美国才意识到形势的严重性
改成强调句：
It was not until the subprime loan had caused great damage to the financial system that Americas realized the severity of the situation.
3.强调句形式3
out of question 毫无疑问
out of the question 不可能的
Q问的形式
A答的形式
例题：
Q:Where did you meet for the first time ?
A:It is in the school___C__we studied together.
A.that
B.who C where D.when
错解：看到It is …___形式把其删掉，看到句子
we studied together in the school.完整就选A.
理解，问的是你们第一次见面是在哪，你答的却是我们是在学校一起学习的。答非所问。
正解：
It is in the school_____we studied together.
we studied together这是个定语,先行词是school，指地点用where
那么这句到底是不是强调句呢？
其实是，只不过省略了that后面的而已
It is in the school where we studied together that we meet for the first time.