i am completely left handed - cant do anything with my right. i use the fork in my left hand though, my dad insisted cos he was embarrassed if we were out in public but i have a tendancy to cut my food with my fork.
i use right handed scissors, but only cos they are more freely available, it doesnt affect the cutting, more can be sore on your hand, thumb cos of the way the scissors are designed, and you have to peer at an angle to see where you are cutting.
playing golf (which i dont do, only crazy golf!) is a nightmare cos you have no choice except to play it righthanded.
things such as tennis can be an advantage cos a righthanded opponent can be unsure how to serve to you, also pool and snooker - you can reach the shots others cant! lots of mega successful tennis stars are left handed!
its impossible to use a fountain pen, you smudge as you right (unless you right from above)
knitting is difficult to learn, as someone else mentioned, if you are learning by copying.
does he write at all? or squiggle?
when i started school i used to write words backwards, starting at the right hand side of the paper and working to the left, would write my name like so
eibbed instead of debbie, but despite teachers and mums efforts, i just changed when i was ready to, i think, so dont worry if he does things backwards, like try to start a book at the end!
lots of things now are for both left and right handed people, like tinopeners