The line that David speaks to the Engineer (which is from a longer sequence that didn’t make the final edit) is as follows:
/ida hmanəm aɪ kja namṛtuh zdɛ:taha/…/ghʷɪvah-pjorn-ɪttham sas da:tṛ kredah/
A serviceable translation into English is:
‘This man is here because he does not want to die. He believes you can give him more life’.