"The native place of Mr Tanaka is an area where much snow use to fall so it a good occasion for skiing I guess, don't you agree?" "No, it is not that I can't, but there is a long time already that I don't go skiing..."
Shouldn't the first example be "I would not say I _don't_ eat natto" (Isn't 食べない is the negative of 食べる to eat, not the negative potential?)
The difference between 食べないこともない and 食べられないこともない is that the former is subjective and the latter is objective. 食べられない=it is normally not fit to eat. 食べられないこともない=it is not that [it is normally not fit to eat]. 食べない=The speaker does not eat. 食べないこともない=it is not that [speaker does not eat].
potential = 見込み、将来性、可能性？？
食べない = do not eat 食べない こともない 食べられない= cannot eat 食べられない こともない
when is "mo" used instead of "ha" for this phrase?