whether
conj.conj. used to introduce two or more possibilities or choices. You use it when you are talking about a doubt or a decision between different things.
conj. introduces an indirect question or a clause expressing an alternative between possibilities. Often functions as a subordinator in nominal clauses following verbs of cognition or communication.
I do not know whether it will rain today.
The manager asked whether the team preferred to meet on Monday morning or Tuesday afternoon.
The success of the merger depends largely on whether the shareholders approve the new leadership structure during the upcoming quarterly meeting.
From Middle English whether, whather, from Old English hweþer, hwæþer, from Proto-West Germanic hwaþar, from Proto-Germanic hwaþeraz, comparative form of *hwaz (“who”). Cognate with North Frisian weđer (“if, whether”), German weder (“neither”), Swedish var (“each, every”), Icelandic hvor (“each of two, which of two”).
Often paired with 'or' to present alternatives. Unlike 'if', it is the preferred choice when a clause follows a preposition or precedes an infinitive.
It depends of whether he comes.It depends on whether he comes.While 'whether' introduces the choice, the preceding verb or noun still requires its standard preposition.