았/었/였 is changed by verb
I am not sure that these English examples are grammatically correct, but let me give you a few example
1. Who did our daughter take after? Me? Or you? >>> 우리 딸은 누구를 닮았을까요? 나? 아니면 당신?
2. Did he eat breakfast yesterday?
>>> 그가 어제 아침밥을 먹었을까?
3. What was i in my previous life?
>>> 전생에 난 무엇이였을까?