yes
Yes. All DS games work on all DS systems.
All games that work on Nintendo DS will work on Nintendo DS-i
Yes Nintendo ds games work on DS, DS Lite and DSI. The DSI does not support gameboy advance games but the DS does.
Of course. All Nintendo DS games work on Nintendo DS Lites. some Nintendo DS/lite games do not work on the DSi, however (like guitar hero on tour) because the DSi has no GBA slot.
Yes it can there aren't games that only work for dsi
Yes.
Yes, the Nintendo DS lite can play DSi games
yes you can use Nintendo ds games in a dsi
Yes, the Nintendo 3DS (as well as the 3DS XL and 2dS) has its own 3DS games that will not work for the Nintendo DS, Nintendo DS Lite, Nintendo DSi, and Nintendo DSi XL.
No Nintendo DS games work on Nintendo DS game consoles and maybe some other Nintendo and not on any of the Xbox or PlayStation game consoles regardless of the country or region.
Nintendo DS and Nintendo DS Lite support Nintendo DS games and Game Boy Advance games. Nintendo DSi and XL only support Nintendo DS games.
The Nintendo DSi is just an upgraded version of the Nintendo DS and DS Lite. The Nintendo DSi plays the exact same games as the Nintendo DS and DS Lite and only plays DS and DS Lite games. Currently, there aren't going to be any DSi games, only more DS games.