[golthin]

Originally Posted by Kaoru Chujo

And I think ka mo shirenai ("may be") is often not quite so uncertain as it seems. I think people often use it to soften the statement, not because they really think there is any doubt.

Originally Posted by margafred

Thanks Kaoru for the explanation and correcting few parts about my post,really appreciate it...i just love how you explain those terms in the simplest way.

Actually, I checked and "tabun" is the word for what Kaouru described above. " ka mo shirenai"
is when you know something but you are not sure if is true or not, or in this case second hand information. You use "ka mo shirenai" when there is a possibility of something. If we put it in percentages, Tabun is something 99% sure, while "ka mo shirenai" has a 50-50% chance.