该结构的基本形式为“too+形容词或副词+to+动词原形”，其意为“太…以至于不能…”：

He is too tired to go any further. 他太累了，不能再往前走了。

He is too shy to speak to her. 他太害羞，不敢同她讲话。

It’s too cheap to be good. 这东西太便宜，好不了(即便宜无好货)。

He is too young to know right from wrong. 他太小，还分不清是非。

有时不定式前可以带有一个由介词for引出的逻辑主语：

The box is too heavy for me to carry. 这个箱子太重，我提不起。

另外，该句型有时可与so [such]…that结构转换：

The box is too heavy for me to carry.

→The box is so heavy that I can’t carry it.

→It is such a heavy box that I can’t carry it.