A pronoun functions like a noun, but they always have an antecedent. There are several kinds of pronouns:

personal will always be 1st, 2nd, 3rd person
demonstrative this, that, these, those; adjectival in function
relative introduces a dependent clause; a DMW
indefinite refers to an indefinite group of nouns
interrogative same words as relatives but always ask a question
reflexive refers back to the subject of the sentence
intensive add emphasis to a statement

Greek Pronouns
Hebrew Pronouns