say it in English paying attention to the use to indefinite pronouns
Some any somebody anybody nobody everybody
1. В комнате никого нет.
2. Кто - Нибудь может ответить на этот вопрос.
3. Никто никогда не видел его.

There is nobody in the room.(There isn't anyone in the room)Can anyone(anybody) answer this question?Nobody has seen him(Anyone has never seen him.)