

Купи какой-нибудь сок.
Buy some juice.
У тебя есть какой-нибудь план?
Do you have any kind of plan?
Давай посмотрим какой-нибудь фильм.
Let's watch some movie.
"какой-нибудь" is in the lesson "Pronouns" (Level 30), along with 17 other useful words. LinDuo has 180 topic lessons like this one, 2,380 words in total. Every word has an illustration, a transcription and pronunciation in a female and a male voice. Just 10–15 minutes a day is enough to learn them all. Free, and works offline.