Fragments. Sentence fragments. Lots of them. Everywhere. In newspapers. In novels. In essays. Even in works by well-respected writers. Fragments make things punchier. Sharper. Almost a staccato.
Usually writers avoid using fragments too much in one paragraph, and instead they save the fragment to emphasise a particular idea. In these cases, you never know when you’ll run into a fragment, so that when it does hit you, you feel the full impact of the author’s deliberate emphasis. It should be a surprise when the reader gets to the fragment. A complete surprise.
Which isn’t to say that the fragment distracts the reader from what it is the writer is saying. Not at all. If used well, the fragment will support the ideas in the paragraph, rather than distract.
Technically, a fragment is grammatically incorrect. A high school English teacher drummed it into my head (figuratively) that fragments are always wrong. Except for famous writers, of course. (Of course.) Now that I know that there are certain times when it is perfectly acceptable for mere mortals to use a fragment, I use them freely. I don’t blame her for misguiding me, since I learned several important lessons in that class, such as “‘Because’ is a subordinate conjunction,” which I had to repeat ten times in front of an amused class. I won’t easily forget that lesson either. Ever.
She did have good reason in teaching the evils of the fragment. Had I not been told that fragments were wrong, I might now write essays that are just littered with fragments. Evil little fragments.