-다가 말다 says you were doing something and quit before finishing: 왜 형 먹다가 말아 'why did you stop eating halfway?', 호주에서 운전면허를 따다가 말았어요 'I started getting my licence in Australia and gave up partway'. After -(으)려다가 말다 it means you were going to and then didn't: 오늘 이거 입고 오려다가 말았어 'I nearly wore this today'. 하다가 만 느낌 is that unfinished, left-in-the-middle feeling.