形式主语
ti + be ……+ that……
it + be ……+ to……
先翻译 that/to后面的句子
that 后面是完整的从句 是 名词从句做主语 逻辑主语是完整句子用 that
to 后面不是完整句子 to do 是不定式作主语 逻辑主语是动词用 to
it was pretty hard for him to bring up child on his own
特别的
is + 系动词 + adj + that
that 后面写 should + do should 可以省略
it is necessary that we should study hard
强调句型
it be……that/who/whom……(be 后面是强调部分)
被强调部分是人 用 that/who/whom
被强调部分是物用 that
ex：you like the book ---->
it is you that like the book / it is you who like the book
it is the book that you like
强调句型与形式主语
强调句型将 it be that 去掉后不会影响原句语法
强调句型可以翻译为 “正是……”
形式主语将 it be that 去掉后会出现语法错误