The website Thebioscopist.com has tracked down the linguistics consultant used for Prometheus in a effort to determinate what David says to the Engineer in the final scenes. Below you can find the translated quote:
This man is here because he does not want to die. He believes you can give him more life.
It has also been revealed that there was a conversation between the Engineer and David originally which didn’t made the cut.
“We’re all going to have to wait for the Director’s cut to see if the conversation between the Engineer and David – and there was indeed originally a conversation, not merely an utterance from David – yields any fruit”. The consultant said.
Thanks to seeasea for the link.