the same!

Hi.. Thank you very much for the detailed explanation. I always thought it were the same. Now I know that they aren't. 고맙습니다 :)

It is very difficult . Even native koreans don't know that. 되다 is formal. 돼다 is wrong. 돼다 is not verb. it is abbreviations 되+어, 되어,....................................돼 되+어서, 되어서.................... ........돼서 되+어야, 되어야............................ 돼야 되+어+라, 되어라.......................... 돼라. 되+었+다, 되었다.......................... 됐다. same so.... 안되어............안돼 안되어서........안돼서 안되어야........안돼야 안되었다........안됐다.