Too means more than is good or desirable.
- It is too hot to go out now.
- The hat is too large for me.
- You smoke too much.
Too can mean ‘also’. It is generally used at the end of a sentence.
- I have got a headache. I have too.
- You can have an apple, but you can’t have an orange too.
To is a preposition.
- I go to office by bus.
- I gave a present to him.