By Purpose:
* Declarative: Makes a statement. Example: "The sun is shining."
* Interrogative: Asks a question. Example: "Is it raining?"
* Imperative: Gives a command or makes a request. Example: "Close the door."
* Exclamatory: Expresses strong emotion. Example: "Wow, that's amazing!"
By Structure:
* Simple: Contains one independent clause. Example: "The dog barked."
* Compound: Contains two or more independent clauses joined by a coordinating conjunction (for, and, nor, but, or, yet, so). Example: "The dog barked, and the cat hissed."
* Complex: Contains one independent clause and one or more dependent clauses. Example: "Because the dog barked, the cat hissed."
* Compound-Complex: Contains two or more independent clauses and at least one dependent clause. Example: "The dog barked because he saw the cat, and the cat hissed in response."
By Form:
* Loose: Main idea comes first, followed by supporting details. Example: "The cat was sleeping on the couch, and the dog was playing with a toy."
* Periodic: Main idea comes last, after a series of dependent clauses. Example: "After the sun had set, the moon rose, and the stars twinkled, the night was finally quiet."
* Balanced: Two or more phrases or clauses of equal length and grammatical structure. Example: "The dog chased the ball, and the cat watched from the window."
Other Classifications:
* Direct: A sentence that directly states a thought or idea. Example: "I am happy."
* Indirect: A sentence that reports what someone else said or thought. Example: "She said that she was happy."
* Active: The subject of the sentence performs the action. Example: "The dog chased the ball."
* Passive: The subject of the sentence is acted upon. Example: "The ball was chased by the dog."
It's important to note that these classifications are not mutually exclusive. A sentence can be both declarative and simple, or both interrogative and complex. The best way to determine the type of sentence is to consider its purpose, structure, and form.