

Помоги мне отпереть дверь, ключ застрял.
Help me unlock the door, the key is stuck.
Сосед отпер нам подвал своим ключом.
Our neighbor unlocked the basement for us with his key.
Я отопру кабинет, как только приду.
I'll unlock the office as soon as I get there.
"отпереть" is in the lesson "Verbs 11" (Level 23), along with 11 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.