对以下句子进行语法和拼写检查，然后纠正错误并给出原因。


1. Me and my friend are going to the movies.
2. The cat chased it's tail around in circles.
3. I could of eaten a horse.
4. Their going to be late for the party.
5. She don't want to go.
1. My friend and I are going to the movies. (The correct order is "I" before the other person, and the subject pronoun "I" should always be used.)
2. The cat chased its tail around in circles. (Incorrect use of the possessive pronoun "it's" instead of "its".)
3. I could have eaten a horse. (Incorrect contraction of "could have" as "could of".)
4. They're going to be late for the party. (Incorrect use of "their" instead of the contraction "they're" which means "they are".)
5. She doesn't want to go. (Incorrect use of the third person singular verb "want" without "s".)