2.  The first word of a complete sentence must start with a capital letter.  Even if a sentence has the other four requirements.  It HAS to have a capital letter at the beginning.

3.  The subject of a complete sentence is who or what the sentence is about.  The subject of a sentence is always a noun or a pronoun, however, it is important to note that while the subject is always a noun or a pronoun, a noun or pronoun is not always the subject.  Sentence fragments and incomplete sentences can lack subjects, as in the following examples: Went to the store. Drove very quickly. Under the stairs.

4.  It is the action or what is going on in the sentence.  It’s always a verb, however it is important to take note that it will always be a verb.  Keep the linking verbs in mind: are, is, am, was, and were.

5.  A sentence is incomplete if it does not contain a complete thought.  “The car drove” is an example of an incomplete sentence because it does not contain a main idea.  The example contains a subject car, a predicate – drove a capital letter and terminal punctuation but without the complete thought it is not a complete thought.

6.  A complete sentence is not complete without terminal (ending) punctuation.  There are 3 types of terminal punctuation.  Period, Question mark, Exclamation point