To - too - two

To, too and two form one of the sets of homophones listed by the then Poet Laureate Robert Bridges.
(For more, see Bridges homophones). AWE has a category listing our articles on each of these..

They are homophones, all pronounced IPA: /tu:/ (though see further on to below). These words have caused confusion to generations of writers in English: it saves much time to learn them thoroughly.

Two is the number '2'.

Too (pronounced long) means

a) as well, also. E.g. 'I like coffee. I like tea too.'

b) overmuch, surplus, excessively. E.g. 'The weather is too hot for me.'

To is the spelling for all other meanings of words that sound like this. 'To' tends to be pronounced very short, IPA: /tʊ, tə or t^ə/, as in 'He's gone to (/tə/) London' or 'You need to (/tʊ/) understand her point of view'. Sometimes, in the representation of informal speech or slang, 'got to' is written as 'gotta'.

A short example of a sentence which may help you to be clear about these three words is the (rather abusive) e-mail note: 'Two fingers to XXX too'.