Sentences are either in the first, second or third person. When we are talking about ourselves we use the first person.
I went to football practice last night.
We are learning a new dance.
Sentences in the first person use the pronouns I and we.
When we are talking to someone else we use the second person.
You can't do that!
Are you coming to my house tonight?
Sentences in the second person use the pronoun you.
When we are talking about someone else we use the third person.
He is very good at swimming.
They live in Manchester.
Sentences in the third person use the pronouns he, she, it and they.
Use this table to help you remember: