

Может быть, завтра будет дождь.
Maybe it will rain tomorrow.
Ты придёшь? — Может быть.
Will you come? — Maybe.
Может быть, позвоним ему?
Maybe we should call him?
"может быть" is in the lesson "Conversation" (Level 36), along with 15 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.