弹钢琴的英语表达是 "play the piano",如果你想说某人正在弹钢琴,你可以说 "He/She is playing the piano",如果你想说某人已经学会了弹钢琴,你可以说 "He/She can play the piano"。希望这个简短的回答对你有所帮助!