‍1. too...to结构中带有表示某种心情或描绘性的形容词或副词时，常表肯定的意义。如：ready, anxious, willing, easy, hard, eager, pleased, happy, delighted, satisfied, kind…等等。如：
She is too ready to get excited. 她太容易激动了。
Johnson is too hard to get along with. 约翰逊太难相处了。
2. too...to 结构之前带有but, only, all, just, simply等词的时候表肯定意义。如：
He is only too eager to see you. 他急于想见到你。
I am all too glad to work with Mr. Wang. 我非常喜欢和王先生一起工作。
3. 当不定式在句中作定语或真正的主语时。如：
There exist too many problems to be solved. 有很多问题有待解决。
It’s too pleasant to travel together with my family. 我和家人一起去旅游很令人愉快。
4. cannot be too … to表示 “越……越好；无论如何……也不过分”。如：
You cannot be too careful to cross the street. 你过街的时候越小心越好。(=cannot be careful enough to)
5. never / not too…to “不太……可以……; 再……也可以……”。如：
One is never / not too old to learn. 活到老，学到老。(谚)
I’m never too busy to spare some time to accompany you. 我再忙也可以抽出时间来陪你。
6. too…not to “很……不会不……”。如：
She is too sensitive not to understand your intentions. 她很敏感，不会不明白你的意图。