Random Riddle: Talking Parrot

A petshop owner had a parrot with a sign on its cage that said “Parrot repeats everything it hears”. Davey bought the parrot and for two weeks he spoke to it and it didn’t say a word. He returned the parrot but the shopkeeper said he never lied about the parrot.

How can this be?
 

Random Riddle: Talking Parrot