my car wont start

[JpnA4Quattro]

.......It has something to do with the battery but when I tried to jump it, it turns once then stops. Could it be the alternator? I had it jumped with my friend's dads car and it started when he reved it, left it running for 15-20 then turned it off and couldnt get it started again even with his dad reving. Yesterday I got my car VAG'ed by dparnas and it showed something about the battery but he said it was probably when I disconnected the bat. when changing my TB. The stealership may be an option now.

[Zodiak]

if it was the alternator the car would die even once you got it running. Sounds like the battery could be dead. 15-20min of idling wouldn't be enough to charge it much. Drive it for atleast 30mins to get enough charge to start it up again. Next time connect the batteries, have the other car rev for about 30 seconds to 1 minute before you try to start it. Then give it a go.