know one's stuff
know about something well

[TahlilGaran] Dictionary of Contemporary English ▲

know stuff
know (your) stuff
[informal]
to know a lot about a subject, or to be very good at doing something.
When it comes to restoring grand pianos, Mr Morley really knows his stuff.

[TahlilGaran] English Idioms Dictionary ▲

know one's stuff
know about something well
The man know's his stuff and is a very good plumber.

[TahlilGaran] English Idioms Dictionary ▲

know one's stuff
To have experience and skill in an activity.
Before trying to make any pottery, it is better to get advice from someone who knows his stuff in ceramics.
Compare: DRY BEHIND THE EARS.

[TahlilGaran] English Idioms Dictionary ▲