I taught myself how to play the piano.

我自学弹钢琴。

《柯林斯英汉双解大词典》

I don't know how to play the piano.

我不知道怎么弹钢琴。

youdao

No. I know how to play the piano. But I'm not good at it.

不是的。我懂得弹钢琴，但我并不精于此。

youdao

But Florence Joplin wanted her son to learn how to play the piano.

VOA: special.2010.01.24

He taught himself how to play the piano.

VOA: special.2010.05.14

Lostwithiel's Steph Newton's musical life started from a young age where she was taught how to play the piano by her grandfather.

BBC: BBC Introducing - Steph Newton

Ray Charles first discovered his gift for music when, at the age of three, his next-door neighbor taught him how to play the piano.

WHITEHOUSE: Celebrating National Mentoring Month

That MP3 file tells the piano what keys to play, and how hard the keys should be played, depending on the style of the artist who recorded the piece.

FORBES: Control Your Piano With An iPhone