What is a pronoun?

A pronoun is a word used in place of one or more nouns. The antecedent of a pronoun is the word to which that pronoun refers. And, pronouns must agree with the noun they replace in number, gender, and person.

What is the difference between first, second, and third person?

"The person speaking" refers to first person. First person pronouns are: I, me, my, mine, myself (singular), and we, us, our, ours, ourselves (plural).

"The person spoken to" refers to second person. Second person pronouns are: you, your, yours, yourself (singular), and you, your, yours, yourselves (plural).

Finally, "the thing or person spoken of" is third person: he, him, his, himself, she, her, hers, herself, it, its, itself (singular), and they, them, their, theirs, themselves (plural).