(sorry;; I should have posted this on 'answer' but clicked a wrong one before) 미쳤어 = (someone is) crazy. you can say she/he is crazy '쟤 (진짜, 완전) 미쳤어" "저 사람 (진짜, 완전) 미쳤어" I think we often add the adverb '완전 or 진짜" (completely) 미치겠어 means " I'm going crazy" "I'm getting crazy" I think it's "wo quai yao feng le" in chinese. you use it when something is bothering you, or driving you crazy. '미쳐다" is a typo.. I think you wanted say "미쳤다" "미쳤다" and "미쳤어" are the same, but I think "미쳤어" is more colloquial. and when you want to say "are you crazy?" you should say "미쳤어?" not "미쳤다?"

谢谢你们，已经清楚的区分它们了，谢谢\(^o^)/

미쳤어的意思是“（我/你/他/她）疯了”，表示已经完成， 미치겠어的意思是“（我/你/他/她）快疯了”. 表示很快就要出现某种情况（疯）。미쳐다(好像你打错了，你想说的不是“미치다”这个词吗？)。 미치다是 미쳤다或者미치겠어的原型形态（字典形态）。

미쳤어 = (someone is) crazy. you can say she/he is crazy '쟤 (진짜, 완전) 미쳤어" "저 사람 (진짜, 완전) 미쳤어" I think we often add the adverb '완전 or 진짜" (completely) 미치겠어 means " I'm going crazy" "I'm getting crazy" I think it's "wo quai yao feng le" in chinese. you use it when something is bothering you, or driving you crazy. '미쳐다" is a typo.. I think you wanted say "미쳤다" "미쳤다" and "미쳤어" are the same, but I think "미쳤어" is more colloquial. and when you want to say "are you crazy?" you should say "미쳤어?" not "미쳤다?"