This error is often indicated by the notation “frag.” on a student’s draft. A fragment is punctuated as if it were a whole sentence, but it is missing either a subject, a verb, or both.
Fragment: Whenever I wash my car.
Complete Sentence: It always rains whenever I wash my car.
Fragments tend to happen because they occur logically before or after the sentence they should be a part of. When we proofread our drafts, many of us do so by reading each page top to bottom and left to right, as we’ve been taught. The problem with this when it comes to editing for fragments is that we automatically join the fragments to whatever sentence they belong with as we read.
In order to get a better grip on your fragment problem, if you have one, a stronger proofreading strategy would be to start at the bottom of the last page and look for the beginning of what you have indicated as the last sentence. Read it aloud. Is it really a complete sentence? If so, move on to the sentence right before that one and do the same thing. If not, correct the sentence and then move on to the next. Work your way backward through your draft until you are finished with the first sentence at the top of page one.
Intentional or unintentional fragments?
Another proofreading tip is to look for sentences which you’ve started with the conjunctions known as the “FANBOYS” (for, and, nor,but, or, yet, so). It’s easy to slip into the habit of starting a sentence with one of these words–especially “and,” “but,” or “or” since that’s how many of us talk or text. We also see sentences in published works where authors have started sentences in this way often to add emphasis to something they are saying. These are intentional fragments. The author is making a specific choice to use them for a particular effect they hope to achieve.
However, doing so is grammatically incorrect. Realize that depending upon the rhetorical situation, an instructor may or may not deduct points for you constructing sentences this way. For example, if you are writing a discussion post, it might be okay. In a formal research paper, it probably wouldn’t be. Another question to ask yourself is whether the use of a fragment helps create meaning or is effective, as in the example above, or does it make it harder for a reader to understand your meaning as is usually the case when fragments are used unintentionally as in the Dos Equis meme. He may be the most interesting man in the world, but still, as a reader we are left to wonder what happens when he uses fragments. The thought is incomplete and the meaning unclear.