고생하다 's usage :) Well, could u pls kindly check if my understanding is correct 1) 어제 내가 넘 고생했어 = yesterday I really suffered /or/ worked hard 2) 너 고생했어 = 아이고... You have worked hard!! Feeling like 불쌍해?!?! 3) 고생했습니다 = thank you for your hard work Thanks ^^