

Кто это на фото?
Who is that in the photo?
Кто хочет ещё чаю?
Who wants more tea?
Не знаю, кто звонил.
I don't know who called.
"кто" 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.