Best Answer - Chosen by Voting
A sentence has to have a noun ( a person, place, or thing) and a verb. There are 3 different types of sentences. A declarative, which ends in a period (.) , an interrogative, which ends in a question mark (?), and a declarative, which ends in an exlamation mark (!) If this is confusing are hard to understand go to this link http://en.wikipedia.org/wiki/Sentence_(linguistics).