too是什么词性
It's too hard to understand spoken English. 理解英语口语太难了。（Unit 1, P2）
◆too…to…意为“太……而不能……”，表示否定意义，too为副词，后接形容词或副词的原级，to后接动词原形。
如：The child is too young to go to school.这个孩子太小而不能去上学。
◆Too…to…可以转化为“so…that…”/“not…enough to…”结构，但要注意“not…enough to…”结构与“too…to…”结构中形容词的意思相反
如：He's so young that he can't take care of himself.=He isn't old enough to take care of himself.
=He's too young to take care of himself.他太小了照顾不了自己
