Coordination and Subordination

Before graduating from high school, most students learn how to write compound and complex sentences that are grammatically correct and properly punctuated.  And they write compound and complex sentences frequently because they don't want their writing to sound choppy.  Unfortunately, many sentences that are grammatically correct and properly punctuated are ineffective.  Ideally, your sentence structure should help your readers understand the relationships between your ideas.  Chapter 42 ("Coordination and Subordination," pages 397-405) of The Longman Concise Companion provides many tips for writing compound and complex sentences that are not only correct, but also effective.