too to用法
too to用法如下：
1、too…to的语法
（1）He is too shy to give a speech.他太害羞，不敢做演讲。
（2）It's too far to get there on time.那个地方太远，不能准时到达。
2、不定式的逻辑主语：有时不定式前可以带有一个由介词for引出的逻辑主语。
（1）It's too expensive for her to buy.太贵了，她买不起。
（2）The box is too heavy for the boy to carry.这个箱子太重，这男孩提不起。
3、不定式是否带宾语：在通常情况下，too…to…结构中的不定式可根据其是否及物来确定它是否带宾语。
（1）He is too tired to go any further.他太累了，不能再往前走了。
（2）The room is too dirty to live in.这房间太脏，不能住。
4、不定式是否用被动语态
（1）The text is too difficult to understand.这课文太难了，理解不了。
（2）The text is too difficult for the students to understand.这课文太难了，学生理解不了。
5、与so[such]…that结构的转换
（1）The child is too young to dress himself.
→The child is not old enough to dress himself.
（2）The box is too heavy for me to carry.
→The box is so heavy that I can’t carry it.
6、too…to…有时可表示肯定意义
（1）He is too clever not to understand this.他太聪明，不会不明白这一点。
（2）Never too old to learn.活到老学到老。
