A/V + 을지도 모르다 functions in a similar way as 'maybe', 'might' or 'I don't know if':
지금 나가지 않으면 늦을지도 몰라요.
If you don't leave now you might be late.
일기 예보에서 나중에 비가 올지도 모른다고 했어요.
The weather forecast said it might rain later.
한국인 이였을지도 몰라서 제가 그에게 어디서 오셨냐고 물어봤어요.
I wasn't sure if he was Korean so I asked where he was from.
(lit. maybe he was Korean/he might have been Korean...)
유명한 배우 일지도 몰라요.
Maybe he is a famous actor.
그는 저에게 아직 화날지도 몰라요.
Maybe he's still angry with me.
내년에 이사할지도 몰라요.
I might move house next year.