Two, To, and Too

Another example of frequently confused homophones (words which sound the same but have different spellings and meaning) are two, to, and too. 

Two

Two is a number:

     Ex.: Two days.

To

Preceding a noun, to can be used as a preposition:

     Ex.: I am going to the store.

When it precedes a verb,  to indicates its infinitive:

     Ex.: I like to dance. 

     Ex.: I need to eat.

Too

Too can be used as a substitute for 'also.'

     Ex.: I want to go, too. (I want to go also.)

Too, when preceding an adverb or adjective, can also mean excessively:

     Ex.: He is walking too quickly.

     Ex.: I'm too tired. 

In Sum

If you're referring to something excessive, use the word 'too.'

To denote the number 2, use the word 'two.'

For everything else, 'to' is appropriate.