Why Identify Sentence Types

     If a group of words is not a statement, a question, a command (including polite invitations), or an exclamation, it is not a sentence. Fragments are often catchy, and they are therefore suitable for titles. A fragment may even have a subject and predicate, as in "if you eat six pepperoni pizzas," but we do not get the feeling that a person who has said this is done speaking. He might go on to ask, "can you afford to go to the ER?" or to warn, "you had better be prepared for a major stomach ache." The point is that the "if" clause all by itself is not a sentence. This exercise will sensitize you to the difference between sentences and fragments by focusing your attention on kinds of complete sentences.