Types of Pronouns :-
A pronoun is a word that replaces a noun in a sentence. Pronouns are used so that our language is not cumbersome with the same nouns being repeated over and over in a paragraph. Some examples of pronouns include I, me, mine, myself, she, her, hers, herself, we, us, ours and ourselves. You may have noticed that they tend to come in sets of four, all referring to the same person, group or thing.
He, him, his and himself, for example, all refer to a male person or something belonging to him. They, them, their and themselves all refer to a group or something belonging to a group, and so on. The truth is that there are many different types of pronouns, each serving a different purpose in a sentence.

Personal Pronouns:-
Personal pronouns can be the subject of a clause or sentence. They are: I, he, she, it, they, we, and you. Example: “They went to the store.”
Personal pronouns can also be objective, where they are the object of a verb, preposition, or infinitive phrase. They are: me, her, him, it, you, them, and us. Example: “David gave the gift to her.”
Possession can be shown by personal pronouns, like: mine, his, hers, ours, yours, its, and theirs. Example: “Is this mine or yours?”

Subject Pronouns :-
Subject pronouns are often (but not always) found at the beginning of a sentence. More precisely, the subject of a sentence is the person or thing that lives out the verb.
I owe that person Rs. 13,000. – I am living out that debt. I is the subject pronoun. He and I had a fight. – This sentence has two subjects because he and I were both involved in the fight.

Object Pronouns :-
By contrast, objects and object pronouns indicate the recipient of an action or motion. They come after verbs and prepositions (to, with, for, at, on, beside, under, around, etc.).
I begged him for more time. He said he'd given me enough time already.