We all know and love Hulk for his very limited vocabulary but as seen in the Ragnarok trailer Hulk has clear speech.
The debuted Hulk comic [May 1962] courtesy of Stan Lee and Jack didn't speak, but by the time he'd gone green for Incredible Hulk #4, he was talking. Albeit in primitive fashion. And oftentimes referring to his alter-ego "Puny Banner."
In the first Avengers movie Hulk grabs Loki and slams him against the floor only saying 'puny God'.
Can someone explain how Hulk has clear speech in Raganrok? [refrence to comics or interviews would be nice!]