edgood  —  Grammar Tips
A grammatically complete sentence has a subject and a conjugated verb, as in Mary sang. A sentence is also an independent clause. If a group of words qualifies only as a dependent clause, it is not a sentence, as in Because we were tired. Many writers use incomplete sentences in their writing. These are technically known as sentence fragments. They might also be called typographical sentences, a group of words beginning with a capital letter and ending with a period. If you use typographical sentences in your style, make certain it is immediately evident that you know what you're doing and that you're not making a mistake. And point out to your supervisor that great writers often use these structures. So there.

The four kinds of verbs enable us to write four basic types of complete sentences:

Four Possible Sentence Types
1A Subject (Actor) John + Transitive Verb in the active voice hit + Direct Object (Recipient) the ball.
1B Subject (Recipient) The ball + Transitive Verb in the passive voice was hit + Actor Phrase (Actor) by John.
2 Subject John + Intransitive Verb ran + Phrase to first base.
3 Subject John + Verb to be is + Predicate Noun the batter.
John   is + Predicate Adjective strong.
  John   is + Phrase at the plate.
4 Subject John + Linking Verb seems + Predicate Noun the team leader.
John   appears + Predicate Adjective quick.
  John   sounds + Phrase out of sorts.

That's it, folks. Every English sentence falls into one of these categories, which vary with the type of verb chosen.