7.11 不定式的特殊句型too…to…
 
1)too…to  太…以至于…
  He is too excited to speak.
  他太激动了,说不出话来。
  ---- Can I help you ? 需要我帮忙吗?
  ---- Well, I'm afraid the box is too heavy for you to carry , but thank you all the same. 不用了。这箱子太重,恐怕你搬不动。谢谢您。

2) 如在too前有否定词,则整个句子用否定词表达肯定, too 后那个词表达一种委婉含义,意 为"不太"。
  It's never too late to mend. (谚语)
   改过不嫌晚。

3) 当too 前面有only, all, but时,意思是:非常… 等于very。
  I'm only too pleased to be able to help you. 我非常高兴能帮助你。
  He was but too eager to get home. 他非常想回家。