Develop AI penpals with adjustable vocabulary levels

大家好, Fellow HSK 4 learner here! I built something for my own learning practice and am genuinely curious if it's useful for other learners or just my weird workflow. I'm hitting the intermediate plateau. DuChinese is starting to run out of interesting content at my level, and I only have tutor sessions 1x/week. My study primarily consists of SRS, reading, and consuming native content (cdramas/youtube). I realized I needed more reps - especially for testing new grammar and vocabulary I'm learning from the HSK textbook in actual conversation context. **The idea:** AI penpals that feel more like texting a real person than doing textbook exercises. https://preview.redd.it/z5ysa16pr02g1.png?width=5278&format=png&auto=webp&s=0388589dabd20ec56869a3caab6a707aef1e3a1c What I tried to build: \- Keep conversations near my level without being too easy or incomprehensible (it has adjustable vocabulary level) \- Hover any character for instant translation so I don't lose conversation flow \- Grammar corrections when I want them (pen icon), hidden when I don't \- Characters with actual personalities - Beijing 996 dev, Yunnan farmer, Chengdu tea philosopher - not "generic chatbot" Example correction from my actual usage: What I wrote: 我刚刚来到这里，什么方便面我都没吃过。 AI caught: • 我刚刚来到这里 → 我刚搬来 (too formal for casual chat) • 什么方便面我都没吃过 → 我什么方便面都没吃过 (都 placement) Recommended: 我刚搬来，什么方便面都没吃过。 https://preview.redd.it/omv3nuxwr02g1.png?width=2418&format=png&auto=webp&s=f4af8825669ea79dcd30201a5a4c0c0b939aa5bd I built this for myself and it's been helpful, but am curious if it fits other's learning styles as well :) Would really appreciate if some intermediate learners could try it for 10 minutes and tell me: 1. Does the vocab level actually feel right for you? 2. Do the characters feel like real people or just fancy ChatGPT? 3. What feels broken or confusing? 4. (Teachers especially) - What would make you warn students away from this? **It's completely free, no signup/account needed**! [https://koucai.chat](https://koucai.chat) 谢谢！ PS: On using AI for learning: As I know some users here are against using AI for learning, I'll say the following: \- Yes, it's built on LLMs \- Yes, it will make mistakes sometimes \- No, this shouldn't replace your tutor or other structured learning (I use it 20-30 min/day between sessions) \- Probably not suited for total beginners I still think the benefits (graded input, active output practice) outweigh the risks for intermediate learners, but I'm open to hearing why I might be wrong about that!