

Это моя маленькая тайна.
This is my little secret.
Мальчик хотел раскрыть тайну старого замка.
The boy wanted to uncover the mystery of the old castle.
В этой сказке много тайн.
There are a lot of mysteries in this fairy tale.
"тайна" is in the lesson "Stories" (Level 33), along with 14 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.