Their: (possessive pronoun) — It implies ownership: Their cat, their house.
There: (adverb) — The opposite of here: Somewhere else. Over there.
They're: A combination (contraction) of the words They and Are. They're nice. They are nice.
Your: It implies ownership: Your dog. (Possessive pronoun).
You're: A combination (contraction) of You and Are. You're pretty. You are pretty.
To: A preposition that means toward. To your house. Also means until. To the end. Until the end.
Too: Means also. I am going, too. I am going also. Can mean excessive. He had too many cookies. That joke is too funny.
Two: A number. One, two, three.
Than and then: Than is used for comparisons. I like apples better than oranges. Then is used for time. I went to a movie, then to dinner. I was at the movie then.
It's: A combination of two words: it and is. It is nice out. It's nice out.
Its: This word is a possessive pronoun. The cat licked its paws. What makes it confusing is that normally you would write: The cat's paws are wet. This indicates the paws belong to the cat. But the word 'its' is an exception to the rule. There is no apostrophe because if there were, it would mean it is!