I understand the alphabet and pronunciation for Hangul. If you wish, I can explain it to you the best I can on IG. It's the best way to start understanding the language, I studied the alphabet for a while so I have a basic understanding.
of course they wouldn't understand if its not in their language. you would need to sign to them in their native language for them to understand. if included common gestures in ther languae mixed in with ASL it wouldnt make any sense to them.