by geezer0305 Tue Oct 16, 2012 2:49 am
Reference: Idioms Ch9 - MGMAT SC.
When used in a positive statement (i.e. without "Not" or "NO"), "DOUBT" should be followed by either a "Whether" or an "If" but not "That".
Eg:
1. I doubt whether it will rain today. - correct (Positive sentence)
2. I have NO DOUBT whether it will rain today. - Incorrect
3. I have NO DOUBT THAT it will rain today. - Correct
4. I DO NOT DOUBT THAT it will rain today - correct
5. I DO NOT DOUBT whether it will rain today - Incorrect
i hope this suffices.
Regards,
geezer