PyTom wrote:Not a middle/high schooler - but total immersion, sort of.
Have a game where the main character is tossed back into revolutionary France, or some other interesting time in history. The POV character thinks in English, but everyone around them speaks in French - and what they say is important to the game. Set it up so that if the player can puzzle out what they're saying, he wins - and if not, that's what the Guillotine is for. (Better, raise the stakes by having a character that the player has to save, by reasoning with the - ... - whoevers.)
Maybe have a button that the player can click - a limited number of times - for a free translation.
The real key here would be to research the words that an age-appropriate student would know, and then limit yourself to those words and concepts. If you do it right, the student should feel like he knows a lot - even though he only knows what he's supposed to.
I'm with PyTom. Total immersion is the most proven method of learning a language, and the most effective. It is what they use in the military and government to teach language - word lists and memorization is, frankly, not incredibly effective, and rather slow. Plus it tends to leave the learner lost without falling back on stock phrases and words, where as with total immersion the learner develops the ability to THINK in the language and form sentences intuitively, instead of running everything through a translation filter in their head.
I learned a lot of Japanese by watching live action Japanese movies without subtitles. And a few weeks of Rosetta Stone (which uses total immersion) taught me more than months and months of classes where I was memorizing and practicing vocabulary lists. As the commercial for Rosetta Stone points out, we all learned our first language by being surrounded by it and struggling to understand what everyone was trying to communicate to us. The human brain is incredible at putting all the pieces together when forced to by necessity.
I like PyTom's idea of forcing the player to figure out French to survive. You would have to be good at providing context to the player. Maybe the player is an English spy sent by the British Monarchy, concerned about the French Monarchy being overthrown, and the player's only hope of survival is to blend in with the French rebels without letting on he or she isn't French. Though anyone of education or noble birth at the time of the French Revolution was expected to know French, as it was the language of trade and diplomacy, and all gentlemen of every nationality were expected to know it.
You might timeshift the game to WW2, and make the player an American or English soldier trapped in a France controlled by the Vichy Regime. To work with the French underground or avoid detection by Vichy French collaborating with the Nazis the player will have to understand French. Maybe the French underground tells the player to grab objects from Nazi offices, and the player will have to puzzle out the French to know the correct object or documents to take, etc. And to paraphrase Pytom, if the player can't figure it out - well, that's what the firing squad is for.