A Pronoun is a word used for or instead of a noun to keep us from repeating the same noun too often. Pronouns, like nouns, have case, number, gender and person. There are three kinds of pronouns, personal, relative and adjective.
A verb is a word which signifies action or the doing of something. A verb is inflected by tense and mood and by number and person, though the latter two belong strictly to the subject of the verb.
An adverb is a word which modifies a verb, an adjective and sometimes another adverb.
A preposition serves to connect words and to show the relation between the objects which the words express.
A conjunction is a word which joins words, phrases, clauses and sentences together.
An interjection is a word which expresses surprise or some sudden emotion of the mind.