Pronouns are words that replace nouns in a sentence to avoid repetition and make communication smoother. Common examples include he, she, it, they, and we. Pronouns can refer to people, animals, or things, and they help clarify who or what is being discussed without constantly repeating names. There are different types of pronouns, including personal pronouns, which refer to specific people or things, and demonstrative pronouns, which point to particular items, like this or those. Additionally, possessive pronouns indicate ownership, such as his, her, or their. Understanding pronouns is essential for effective communication.