英语中强调句型就是采用it is +强调部分+that……

强调部分可以为主语,宾语,表语,状语……

比如：对you are my friend.强调主语就是:

it is you that are my friend.

It is (was) 被强调部分+that (who) + 句子其他部分。

此结构强调的成分仅限于主语，宾语和状语。强调句的连词只有两个，that和who。当强调的部分是人，且为句子的主语时，才用 "who"，其余用that。

原句： My father did the experiment in the lab yesterdayevening.

强调主语： Itwas my father who did the experiment in the lab yesterday evening.

强调宾语： Itwas the experiment that my father did in the lab yesterday evening.

强调时间： Itwas yesterday evening that my father did the experiment in the lab. (注意不用when)

强调地点： Itwas in the lab that my father did the experiment yesterday evening.

如果想强调谓语,那么一般用助动词do或者他的对应时态进行强调.比如：your father asks you to do your homework.强调谓语ask.如下：your father does ask you to do your homework.