different between 어 & 오 / 에 & 애 ?
as a non-Korean speaker, can you give some advice how we could understand them better and the meaning behind all these. and the right way to use them. tq

Question

Answer

For 오, just say "Oh" without the w-sound at the end.

어 is like a mix of 오 and 아. Make your mouth round as if you're going to say "Oh" and say "Ah" instead. If you do it correctly you'd pronounce something like the O in "on".

As for 에 and 애, check out this video:
https://www.youtube.com/watch?v=Ub6QjPkfGHI