他七岁时开始学习弹钢琴的翻译：At the age of seven he began learning to play the piano 什么意思？中文翻译英文，英文翻译中文，怎么说？

青云英语翻译

He began studying piano at seven

At the age of seven he began learning to play the piano

When his seven years old starts to study the ball piano

He began learning the piano at 7 years old

At the age of seven he began learning to play the piano