Tried having it generate German puzzles (normal sentence with a missing word like "der" or "dem" or so) after someone blogged about that it would be worth like

Tried having it generate German puzzles (normal sentence with a missing word like "der" or "dem" or so) after someone blogged about that it would be worth like 90% of a language teacher for 1% of the price. I'm not very good at German but most things it proposed seemed wrong to me. The whole point is that I don't have to talk to a native speaker but I decided to show the conversation to one who then said something like "yeah no, you're correct half the time and the computer is wrong even more times" Maybe I should feed it bits from Wikipedia and have it censor word classes for me (or is part-of-speech identification by human-made algorithms reliable?), but that's a lot more involved to code up than prompting it "hey just do this task". I'm sure I'm just holding it wrong and it can be a useful language teacher in some way, e.g. I have had good results with 1:1 translations, but don't expect it just does what you ask it when you can't verify the result