The adverb too goes before the adjectives and adverbs it modifies.
- She drives too fast.
- She spoke too slowly.
- The weather was too hot.
- Her performance was too lousy.
The adverb too is often followed by an infinitive structure.
- She is too old to enter school.
- It is too hot to go out.
The infinitive structure can be preceded by for + noun / pronoun.
- The tea is too hot for me to drink. (Here the phrase for me is actually the subject of the infinitive to drink.)
- The problem was too difficult for them to solve.
Too can mean also. In this case, it goes after the adverb and is usually set off with a comma.
- She is beautiful. She is intelligent, too. (= She is also intelligent.)
- She not only sings; she plays the piano, too. (= She also plays the piano.)