This document discusses the four types of sentences according to structure: simple, compound, complex, and compound-complex. It defines each sentence type and provides examples. Simple sentences contain one independent clause. Compound sentences contain two or more independent clauses joined by coordinating conjunctions. Complex sentences contain one independent clause and one or more dependent clauses. Compound-complex sentences contain two or more independent clauses as well as one or more dependent clauses. The document aims to help students understand sentence structure and the different types of sentences.