Too is often used before an adjective or adverb; you will never see it before a verb. Too is different from 'very'.
Too can mean 'more than enough' or more than necessary'. It often implies negativity.
Adjective -- You're never too old to try new things.
Adverb -- He spoke too quickly for me to understand what he was saying.
Too can mean 'also'. If left to the end of a sentence, please separate too with a comma.
1. Alain: I like dogs.
Jeff: I do,too.
2. Betty: I want to go shopping.
Caroline: Can I come? I want to go, too.
To can be used in several ways.
1. Most people recognize it as a preposition, referring to a place, direction, or position.
- He went to the store.
- Look to the right.
2. To is used when creating the infinitive. The simple infinitive is created by joining
to + the simple form of a verb. Here is a list of common verbs that can be followed by the infinitive: want, need, hope, decide, promise, agree, forget, and try.
- I want to go home.
- I need to drink some coffee.
3. Another way to use to is as an ellipsis. An ellipsis normally happens when an expression is used for the second time, after the complete form has already been used once.
- I forgot to by milk. I didn't mean to.
Alex B: Do you want to get some coffee?
Lisa: No, I don't want to.
4. To can be used to describe range, which often replaces the dash in expressions like 9 to 5.
5. To is also used when expressing purpose, which means the same as 'in order to'.
- I went to the store in order to buy a present for Brad.
- I went to the store to buy a present for Brad.