怎样判断句子是否是强调句?

it is ______that/who
当去掉“it is that/who”仍可成为一句话，那么就是强调句
例如：It was in the park that they had a picnic yesterday.
可变为：They had a picnic in the park yesterday.
我觉得这种方法是最容易记住的，比那些语法里的术语要好记，当然你也可以看看语法书。

强调句的句形是it is ...（要强调的内容）that
要看它是不是强调句，就把it is ... that 去掉，再看这句话完整不完整。完整的就是强调句

举例：I bought a pen in a store.

强调是“我”买而不是别人买，就把我放在句子中间it is I that tbought a pen in a store
强调买的是“笔”，而不是别的东西，也这样写。it is the pen that I bought in a store
你看看，去掉之后，上面的句子仍然完整。

记得了，这个句型强调的是名词

It is that是强调句