540　It is +形容词+of sb.+to do sth.

　用it 作形式主语的句型结构中，如果作表语的形容词是clever, good, nice, kind （善良的），foolish （愚蠢的），wrong等，不定式前要用of sb. 引出不定式动作的执行者，不用for sb.。

It is clever of her to say so. （正）她这样说话是很聪明的 。

It is clever for her to say so.（误）

It is very kind of you to help me. 你帮助我真是太好了。

It is foolish of Jim to do like that. 吉姆那样做是愚蠢的。

It is very nice of you to lend me the book. 你把那本书借给我真是太好了。

It is good of her not to tell him the news. 她没把消息告诉他真是太好了。（不定式否定式 ）