What David says to the Last Engineer in Prometheus
According to the man himself, Dr. Anil Biltoo, who worked as the linguist consultant for Prometheus and who also played the linguist teacher (image below), David says to the Engineer “This man is here because he does not want to die. He believes you can give him more life” in translated form.
Dr. Anil Biltoo also reveals there will be more dialogue shown from that scene in the Director’s Cut, and it is not just a one-way conversation between David and the Engineer. Unfortunately, the professor didn’t elaborate further on the the extended dialogue probably due to contractual reasons.
A lot more at the source http://thebioscopist.com/2012/06/20/the-linguistics-of-prometheus-what-david-says-to-the-engineer