my homework is to find pronouns(thats no problem) and then i have to tell whether it's nominative, objective, or possessive. i don't understand any of that, i've tried but my book just doesn't make any sense.

nominative = used as subject of the sentence (she, they, I, etc.)

objective = used as direct object, indirect object, object of a preposition (her, them, me, etc.)

possessive = shows ownership (her/hers, their/theirs, my/mine, etc.) One thing to remember is that pronouns' possessives do NOT have apostrophes.

=)