The document discusses different types of sentences according to their structure: simple, compound, complex, and compound-complex. It provides examples of each type and explains their characteristics. The key differences are: simple sentences contain one independent clause, compound sentences contain at least two independent clauses, complex sentences contain one independent clause and at least one dependent clause, and compound-complex sentences contain at least two independent clauses and at least one dependent clause. The document also reviews subordinate and independent clauses.