whether and if

  1. In reported question , we can use both whether and if
  • I’m not sure whether/if I’ll have time
  • I asked whether/if she had any letters for me
  1. We prefer whether before or especially in a formal style
  • Let me know whether you can come or not
  1. After discuss, only whether is possible
  • We discussed whether we should close the shop (not we discussed if..)