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perhaps; possibly; maybe; by any chance; if I'm not mistaken
if; in case; in the event that
もしかしてあなたは田中さんですか。
By any chance, are you Mr. Tanaka?
もしかして道を間違えたかもしれない。
Perhaps I might have taken the wrong road.
もしかして今日は休みだったのかな。
I wonder if perhaps today was a holiday.