

Это очень важное правило.
This is a very important rule.
Ты знаешь это правило?
Do you know this rule?
В армии есть такое правило.
There is a rule like that in the army.
"правило" is in the lesson "Military" (Level 31), along with 13 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.