[primitivesuave]

This is a neat concept and worked great for a German conversation. Adding a pronunciation/text-to-speech element would make it a lot more useful for beginners and is especially important for any tonal languages. It might also be helpful to support spaced repetition, i.e. be able to mark an AI response as useful and then be prompted to recall it later on. There might even be some clever prompt engineering to get GPT to try favoring certain words/phrases in its response based on proficiency level.

From a business standpoint, I would suggest focusing on one language, and targeting people who are learning it with the AI + courseware. One of the GitHub founders started chatterbug.com specifically to teach German, and they delivered an exceptional experience that was easily worth $100/month (including video chats with a German coach). Now they've taken that successful model and expanded to other languages. If I could get the same conversation going with an AI, that's great, but the real secret sauce to any online learning play is the content.