It is unknown if/whether he will come.


Senior Member
It is unknown if they will sign the agreement.
It is unknown whether they will sign the agreement.

Do the two sentences both correct? I know they are both ok in informal occaison. But when I write this sentence in a formal document, is the second one better than the first one? Or are they still both perfect?
  • entangledbank

    Senior Member
    English - South-East England
    There's nothing particularly informal about 'if'. Although 'whether' is more likely to be used, it wouldn't sound wrong to use 'if' at any level of formality.