You use too after mentioning another person, thing, or aspect that a previous statement applies to or includes.
'Nice to talk to you.'—'Nice to talk to you too.'
“和你交谈很高兴。” “和你交谈我也很高兴。”
'I've got a great feeling about it.'—'Me too.'
“这让我感觉好极了。” “我也是。”
You use too after adding a piece of information or a comment to a statement, in order to emphasize that it is surprising or important.
We did learn to read, and quickly too.
我们确实学会了认字,而且学得很快。
You use too in order to indicate that there is a greater amount or degree of something than is desirable, necessary, or acceptable.
Leather jeans that are too big will make you look larger.
皮裤太大会让你显得更胖。
I'm turning up the heat, it's too cold.
我要把暖气的温度调高些,天太冷了。
You use too with a negative to make what you are saying sound less forceful or more polite or cautious.
I wasn't too happy with what I'd written so far.
我对自己目前所写的东西还不是非常满意。
all too , only too
You use all too or only too to emphasize that something happens to a greater extent or degree than is good or desirable.
She remembered it all too well.
她对这事记得极其清楚。