Sentences

Clauses
• Independent Clause: An independent clause contains a subject and a verb and expresses a complete thought. It can stand alone as a sentence by itself. An independent clause is like an adult person: it is independent and can “live” by itself.
• Dependent Clause: A dependent clause begins with a subordinator such as when, while, if, that, or who, followed by a subject, verb, and complement. It does not express a complete thought and cannot stand by itself as a sentence. A dependent clause is like a little child: it cannot “live” by itself.

Sentences
• Simple Sentence: A simple sentence is one independent clause. Like an adult person, it can “live” alone.
• Compound Sentence: A compound sentence is two or more independent clauses joined together, like two adults joined together in marriage. Each clause is of equal importance and could stand alone. There are three ways to join independent clauses to form a compound sentence:
With a coordinator: I enjoy playing tennis, but I hate playing golf.
With a conjunctive adverb: I enjoy playing tennis; however, I hate playing golf.
With a semicolon: I enjoy playing tennis; I hate playing golf.
• Complex Sentence: A complex sentence contains one independent clause and one (or more) dependent clause. It is like a mother with one or more children depending on her. In a complex sentence, one idea is generally more important than the other one. The more important idea is placed in the independent clause, and the less important idea is placed in the dependent clause.
• Compound—Complex Sentences: A compound—complex sentence is a combination of two or more independent clauses and one or more dependent clauses. It is like a family of two adults and one or more children.

Source: Oshima, A. & Hogue, A. 1991 Writing Academic English