Here are 5 examples of pronouns in sentences:
1. I went to the store, and I bought some milk. (I replaces the name of the speaker)
2. She is a talented artist, and her paintings are beautiful. (She refers to a female person, her refers to her possessions)
3. The dog wagged its tail happily. (Its replaces the noun "dog")
4. They are coming to visit us this weekend. (They refers to a group of people)
5. This is the book I was telling you about. (This refers to a specific object)