difference between 짓다 and 지다
짓다 = to make / build
in present tens informal it's irregular and ㅅ remove so it become: 지어
other side
지다 = lose
in present tens informal it become: 지어

So how do I know the difference?

Question

difference between 짓다 and 지다
짓다 = to make / build
 in present tens informal it's irregular and ㅅ remove so it become: 지어
other side
지다 = lose
in present tens informal it become:  지어

So how do I know the difference?

Answer

Context clues. Infer which one they mean by the context of the sentence/convo

Answer

지다 becomes 져. Nobody would say 지어 in real life, using "long" versions is a bit literary.
In the same way that for 주다 and 보다 we say 줘 and 봐, instead of the long 주어 and 보아.
내가 졌어 = I lost (nobody would say 지었어)

I don't think we can shorten 짓다 to 져, it seems like it's always 지어, 지었어.
제 한국 친구가 지어 준 이름이에요 = My korean friend made this name for me 
져 준 wouldn't sound right, to my ears at least. I'm not a native speaker so I might be wrong.

Answer

Context is always very important. We do that in English too.