What are the three types of Object pronouns?

There isn't a clear categorization of object pronouns into "three types." Object pronouns are simply pronouns that act as the object of a verb or preposition.

Here are the object pronouns in English:

* Me

* You

* Him

* Her

* It

* Us

* Them

These pronouns are used in sentences like:

* He gave the book to me. (me is the object of the preposition "to")

* She called him on the phone. (him is the object of the verb "called")

Perhaps you're thinking of a different aspect of pronouns? Could you clarify your question?