adverb
Expresses a tentative guess or possibility, often used when asking a question or making a suggestion. Similar to もしかすると but slightly more casual.
See also: もしかすると
もしかして、田中さんですか?
By any chance, are you Mr. Tanaka?
Perhaps it might rain.
adverb
if; in case; in the event that
Used to introduce a hypothetical condition, often with a sense of 'if it happens that...'. Less common than sense 1 and can sound slightly formal or literary.
もしかして彼が来なかったら、私が代わりに行きます。
If he doesn't come, I'll go instead.