1. To (preposition) - Too (adverb) - Two (number)
2. There (adverb) - Their (possessive pronoun) - They're (contraction of "they are")
3. Hear (verb) - Here (adverb)
4. See (verb) - Sea (noun)
5. Right (adjective) - Write (verb)
6. Pair (noun) - Pear (noun)