Whys & Wherefores
If your idea is -'I suppose-' or -'I imagine-', you can use -'no doubt-'. In other words, we use it when we think that what we are saying is likely...
Sir what is the difference between 'no doubt' and 'without doubt'? L.Laxmaiah, Koonavaram, Khammam.
If your idea is 'I suppose' or 'I imagine', you can use 'no doubt'. In other words, we use it when we think that what we are saying is likely to happen, or when we think it is true. For example, No doubt you’ll want breakfast before you leave tomorrow.
We can use there is no doubt that … when we are very sure about our opinion. We use it in formal situations: He’s never got any medals, but there’s no doubt that he is a meritorious person. Without doubt is even more formal. We use it when we are absolutely certain about our opinion: Musician Ilayaraja is without doubt one of the greatest composers of melodious music of all time.