Personal pronouns are used to replace nouns or names we are familiar with. The personal pronouns include: “I,” “me,” “she,” “he,” “you,” “we,” “they,” “it,” etc. With pronouns, you can avoid repetition by not constantly mentioning names, especially when what you are referring to is obvious.
Imagine a conversation between two friends, Jack and Jill:
Here is another example, a conversation between a mother and her daughter:
In this example, instead of responding that the exam was great, “exam” was replaced with “it.” To avoid repetition and because there is only one noun, the noun was changed to a personal pronoun.