Especially in those cases, I used to give up and translate the entire message from English, which kind of defeats the purpose and interrupts the learning process.
So I started prompting GPT. I’d write my message with wildcards or notes for the parts I didn’t know, and it would return a corrected version. That worked well, but reusing the prompt each time became tedious.
So I built a wrapper around it.
Now I can type in the target language, mark unclear parts with curly braces {like this}, and get an instant corrected version with explanations. I also added a history feature so I can review what I got wrong, and I plan to build more on that soon (eg. summary of areas or words to review).
This app is for language learners who want to practice writing without feeling insecure about mistakes or breaking their flow by switching to a translator.
I hope you find it useful!
I've done a lot of research into LLM translation for my product[0], and I'm currently working on a deep translation service that provides reliably human-level translations.
I don't know what model you're using, but GPT-4.1 is probably the best for your use case - it's in the top few % for nearly every language, and has a low standard deviation, while also being relatively low latency and low cost.