Subject and object pronouns are used to replace nouns in sentences. They help to avoid repetition and make sentences more concise.

Subject pronouns are used when the pronoun is the subject of the sentence. They include: I, you, he, she, it, we, and they.

For example: - I am going to the store. - She is reading a book.

Object pronouns are used when the pronoun is the object of the sentence. They include: me, you, him, her, it, us, and them.

For example: - John gave me a gift. - Can you help her with her homework?

It is important to use the correct pronoun based on whether it is the subject or object of the sentence. Using the wrong pronoun can lead to confusion or grammatical errors.