A sentence is a group of words that expresses a complete thought. It typically contains a subject (who or what the sentence is about) and a predicate (what the subject is doing or what is being said about the subject). It begins with a capital letter and ends with a punctuation mark. Here are the main types of sentences based on their purpose: Declarative Sentence: Makes a statement or expresses an opinion. It ends with a period. Example: The cat is sleeping. Interrogative Sentence: Asks a question. It ends with a question mark. Example: Are you coming to the party? Imperative Sentence: Gives a command, makes a request, or offers advice. The subject (you) is often implied. It ends with a period or an exclamation mark. Example: Please pass the salt. Exclamatory Sentence: Expresses strong emotion or excitement. It ends with an exclamation mark. Example: What a fantastic goal!