Answer: Gramatically: define in terms of person (first second or third)
number (singular or plural) and gender (masculine, feminine, neuter) English has neuter, French does not. and case: nominitive, objective, dative and possessive. (English dative and objective are identical not so in French)
This is probably way more than you wanted to know. . .
Explanation: First person is the pronoun that refers to the speaker: je, me, moi,mon= singular, nous, notre=plural (the couple or group including the speaker)
second person pronouns refer to the person spoken to: tu, te, toi, ton= singular, (familiar) vous, votre=plural or "singular,polite"
Third person pronouns refer to the person(s) or thing(s) spoken about. il,elle, le,la, lui, son, ils, elles,la, les, leurs, ses. . .
Nouns are generally considered third person, singular or plural; Possessive if ownership is indicated by adding -'s. They don't change form for nominative or objective case.