The short sentence (or just one word with a full stop) is a useful tool that can be effective during action sequences or can drive a point home. One of my favourite examples of its power was in one of the Stephen Donaldson books of the Chronicles of Thomas Covenant. In the particular section I’m talking about he describes the opening of a door into the land of the dead. He describes the surroundings, the reactions of those present, the intense, powerful, terrifying atmosphere of it all, and how this character stepping out is recognized:
Those of you that haven’t read the Chronicles of Thomas Covenant, or read the books and didn’t enjoy them, will probably emit a small titter at this point. However, when I was reading them I was utterly absorbed and so I knew that Kevin wasn’t a spotty geek with a bad dress sense and a problem with BO. He was Kevin Landwaster who performed the Ritual of Desecration to annihilate an entire land.
Short sentences can be the choice of those who haven’t quite got to grips with double, multiple and complex sentences, or learned how to use co-ordinating conjunctions. They can be the choice of those aping Hemmingway or Chandler and failing to get what those writers were about. And they can be heavily over-used.
I’ve read published books where this over use is prevalent. The writer is driving his words into your head like nails into a block of wood: bammity bammity bam, de bam de bam de bam. After a while you get a headache. Yeah, I get it, stop with the hammering already. I’m got a brain here between my ears that can turn your words into images; that can model your story in my head. Your story doesn’t change just because you’re putting the words there with a literary machine gun.
Use short sentences sparingly.