Pronouns are words that replace nouns. Some examples include:
* Personal pronouns: I, you, he, she, it, we, they
* Possessive pronouns: mine, yours, his, hers, its, ours, theirs
* Reflexive pronouns: myself, yourself, himself, herself, itself, ourselves, yourselves, themselves
* Demonstrative pronouns: this, that, these, those
* Indefinite pronouns: all, any, each, every, none, some, somebody, anyone, everyone
"Able" is an adjective describing the capacity to do something. It doesn't replace any nouns or act like a pronoun.