The game would probably go towards vocabulary or basic grammar, because it would be about learning a foreign language.

I just finished another project, so I might make a prototype of this to try it out, I have some doubts about a vocabulary turn based rpg...

A game about battling a comma splice xD talk about niche market.

I'm not really sure about the actual value of this type of thing educationally. Presumably its for very little kids. Older kids wouldn't buy the premise. What's your learning target for the game? A few basic words or sentences?

Actually, it's something I wished to have for myself. A fun way to burn those words to memory. Especially verb conjugation, which sometimes I realize I can't conjugate really basic verb forms.

My market of choice will be the Android Market, since I find that to be well receptive of RPG games. I wanna make a game that you can learn while playing, but that you can also play without having learning as the objective, you know? So the main focus will be to make the battle system pretty fun!

I haven't really decided on the story as of now, but I've started creating the battle system. I have decided, with my artist, that the game will be set on the present days, with a school theme, most likely.