What is going a noun a verb or adjective?

The only Word that is required is a verb; most sentences have a subject, the subject can be a noun or a pronoun. The sentences that consist of only a verb are imperative and exclamatory sentences. Not all sentences have an adjective. Example:

Exclamatory Sentence: Stop!

(the subject of this sentence is implied, either the name of the person who should stop, a noun, or the pronoun 'you')

Imperative Sentence: Clean your room.

(again the subject is implied, either the name of the person or the pronoun 'you')

All other kinds of sentences require a subject (a noun or a pronoun) and a verb. Example:

Subject noun: Margaret has a new dress.

Subject pronoun: She has a new dress.