Grammar Handbook: Sentence Types

The Center for Writing Studies, The University of Illinois at Urbana-Champaign

Sentences can be either simple, compound, complex, or compound-complex.

:: The Simple Sentence
Simple sentences have only one independent clause. There are no dependent clauses, and the sentence must be limited to one subject and one predicate. The sentence may contain modifying words or phrases:

Grammar class is boring. "Magma" is a French progressive rock band.
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:: The Compound Sentence
Compound sentences are composed of two or more independent clauses, which are joined by a coordinating conjunction or a semicolon. One should always use a comma before any coordinating conjunction that connects two independent clauses:

Sissy likes "Magma," but she thinks grammar class is boring. Timmy likes grammar class, so he does not like "Magma."
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:: The Complex Sentence
Complex sentences use one independent clause and one or more dependent clauses:

When Sissy is in grammar class, she often dreams of the next Magma show. ("When Sissy..." is a dependent clause, "she often..." is an independent clause.)
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:: The Compound-Complex Sentence
The compound-complex sentence joins a compound and a complex sentence together. It should contain two or more independent clauses and one or more dependent clauses:

Magma sings in a language they created, and they feel that proper grammar has no place at their shows, which are often quite obnoxious.
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:: Comma Usage
For proper comma usage with each sentence type, see Restrictive and Nonrestrictive Clauses.
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