

Он ушёл час тому назад.
He left an hour ago.
Мы познакомились год тому назад.
We met a year ago.
Это было лет десять тому назад.
That was about ten years ago.
"тому назад" is in the lesson "When" (Level 42), 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.