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 it, 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。