While at the mental institute, Eddie Murphy is asked to speak to an orangutan. The orangutan does not respond to him until he is on his way out, at which point it says "Adios, muchas gracias por nada" (Bye, thanks a lot for nothing).

He also says "Tu conoces Will Smith?"

"Tu" meaning you, and "conoces" meaning know. The slip-up is that when you are talking about knowing a person, like in this case, you would need to put the word "a" in between "conoces" and "Will Smith." Otherwise it's bad grammar.