Genesis 12:4 reads: Vayelech Avram... Avram went according as HaShem had sproken to him, vayelech Lot ito, and Lot went with him. But the next verse reads: Vayikach Avram.. et Lot, and Avram took Lot, vayetzu lalechet, and they went out on their way to... Genesis 13:1 again describes both men going on their way, but this time it says Vaya'al Avram... v'Lot imo, and Avram went up, and Lot with him.
First I would like to know if Lot went with Avram or if Avram did take Lot, or are both statements in line with eachother? Secondly I would like to know to what the -o ending in ito and imo is revering to: who is the him in each case; is it Lot or Avram?
(P.s. if someone could explain me when - in which case - to use עמו or אתו I would appriciate it; both are translateable as 'with him').