Yes they do all of the ds games work on any Ds or dsi it doesnt matter about the country u are in
DS games are region-free, a Japanese DS game will work fine on a DS from the US.
No. the 3ds games have a tab on them so that they do not fit into another ds, if it went in, the game might break the dsi.
Yeah, they can
Yes, a Japanese version of Pokémon HeartGold will work on a DS from Australia. The Nintendo DS can play all games regardless of what country they originate from.
No. Currently, as of February 2014, the 3DS is the DS with the best and up to date features
Yes, DS games are region free.
Yes, but most games are only in Japanese. so if you know Japanese go for it!
Yes. The DS lite is not region locked, a Japanese model will play DS games from the US.
If you have a Japanese System then it will work. IE iF you import a Japanese DS game, then you need to play the game on a Japanese DS.
Yes, you can, DS games are region free.
Nope
yes any language games