tap on

tap on (something)

1. To strike something lightly and swiftly. You're never going to drive the stake into the ground tapping on it with your hammer like that. I could have sworn I heard someone tapping at the window, but there was no one there when I got up to check. The singer tapped on the microphone to see if it was one.
2. To strike someone or something lightly and swiftly on a particular spot or part. In this usage, a noun or pronoun is used between "tap" and "on." I turned around when someone tapped me on my shoulder. He always taps soda cans on their lids before opening them.
See also: on, tap

tap someone or something on something

to make one or more light blows on some part of someone or something. Someone tapped me on the shoulder, and I turned around to see who it was. I tapped the drum on the top to find its pitch.
See also: on, tap

tap on something

to make one or more light blows on something. Who is that tapping on my windowpane? I wish you would stop tapping on the tabletop.
See also: on, tap