> it must be multilingual and dynamically switch between languages pretty much per word
Not abundantly obviously a satire and so interjecting: humans, including professional "simultaneous" interpreters, can't do this. This is not how languages work.
You can speak one language, switch to another language for one word, and continue speaking in the previous language.
You can speak one language, switch to another language for one word, and continue speaking in the previous language.