Yes they do.All DS games should work on DS, DS Lite, and DSIstupid
DS games are region-free, a Japanese DS game will work fine on a DS from the US.
No, they will not work.
Yes, DS games do work in a DSi XL. The DSi XL is part of the DS line, so DS games are meant to work with it.
All DS games work on the NDSi.
All DS games work on both the DS and the DS Lite. Games that require a GBA cartridge slot (like the Guitar Hero games) do not work on the DSi, as the GBA slot has been removed. also dont try 3ds games on any ds ( but 3ds) it wont work but you can play ds games on it :( but not 3d
Yes, they will work since DS games are not region locked.
All games that work on Nintendo DS will work on Nintendo DS-i
Yes.
No you cannot, your best bet would be a sequel to the game for the DS.
Yes, the DSi can play DS games
Yes it will because DS games are not region locked