What are the uses of pronoun it?

The pronoun 'it' takes the place of a noun for a thing.

The pronoun 'it' is a third person (a thing spoken about), singular, personal pronoun.

The pronoun 'it' functions as the subject of a sentence or a clause, and as the object of a verb or a preposition.

The plural form for the third person, singular pronoun 'it' is 'they' as a subject or 'them' as an object.

Example uses:

subject: The puppy was clean and brushed. Itlooked so cute.

object: You may borrow the book. I think you will enjoy it.