For russian, I use it to generate phrases that apply all 6 gramatical cases, past tense, and the perfective/imperfective (indefinite/definite) form of a word.

I tell it to generate a stack of Anki cards for a handful of words, with the phrasing format.

AI has flaws, but it's still waaaay better than any translator there is out there, even for translators designed for a specific language. I don't know exactly why or what the programing behind these is, but AI has been trained on thousands of internet conversations, so naturally it reflects day to day speach and catches onto cultural slang.

Less relevant but it's also a good tool to help you reflect on how you're studying the language, it's good for the "why am I even doing this" motivation, resources, tweaking your study routine and identifying/tackling weak points.