You probably remember from high school English that there are three basic types of sentences: simple, compound, and complex. Of course, there is the hybrid, compound-complex, so I guess that makes four types. When I say writers should vary sentence structure, am I saying we need one of each of these basic types in every paragraph?
A writer can utilize a healthy mixture of these basic types, of course, but there are other ways to create variety.
The fragment. In formal writing, the kind we learned to do for school, using fragments is a no-no. Not so in fiction, especially in dialogue. The fact is, we rarely speak in complete sentences in real life, so our fiction characters certainly should be allowed to use fragments, too.
But even in non-fiction and in the narrative parts of our fiction, fragments can be effective. I hope you already picked up on the fragments I used earlier in this post to illustrate the point. Fragments are a great change of pace, which means they are eye-catching, attention-arresting, thought-stirring.
They should be used judiciously, which means they should not be used too frequently or for no particular purpose. They are special because they are not the norm, and as such they should be reserved for special occasions.
When sprinkled into the text with thought, fragments can give needed refreshment to prose.