Technically it can already talk using its own language.
To talk with human words requires a bump in intelligence which would end up in severe depression once it realises the dynamics of ifs existence.
As you didn’t wish for that intelligence you’re now stuck with a dog that barks with human vocal cords. Its first wish was made using body language for the genie to pet them. The second wish was to trow a stick.
Do you have your phone near you when you do this or not?