know stuff

know (one's) stuff

To be very knowledgeable or skilled in some area. I think Nicole is our best candidate for the job—she really knows her stuff when it comes to corporate accounting.
See also: know, stuff

know one's stuff

 and know one's onions
to know what one is expected to know. I know my stuff. I can do my job. She can't handle the assignment. She doesn't know her onions.
See also: know, stuff
References in periodicals archive ?
And if you don't believe me, think of Matt Damon: Damon has four kids and I have not a clue even what their names are and it is kind of my job to know stuff like that.
I write the children a letter and say I'm totally honoured, but unqualified for the role, but I'll talk to them when they're 16 and that I know stuff about their parents, so when they're really annoying them, they can come to me and I'll dish the dirt
I PUT them into two categories - those that are very plausible and probably could sell you anything on the shopping channels and those who just know stuff.
But we all know stuff catches up with us eventually.
I've been told he should have an agent, that he's a 'Messi in the making', that the fact he is two-footed and doesn't look at the ball when he dribbles is terribly advanced for his years, all by dads who know stuff and almost certainly haven't had the off-side rule explained to them 42 times until their eyes glazed over and are still none the wiser.
He always takes things to heart and his father doesn't know stuff so that's when everything gets intense.
He said: "He would be one of my favourites, and Arthur C Clarke - people who really know stuff and can make science really interesting.
Your body hurts and you can't communicate with anyone, and you think you know stuff before you know it and your parents are idiots and they're embarrassing.
His mother who was there with him all the time, she started picking up on it, you know stuff was missing, money here, stuff like that.
The Holiday Inn Express brand understands that when you stay smart, you know stuff, and so the brand wants to give consumers the chance to share their smarts with others through popular social media outlets.
He knows I'm one of the captains, and he'll let me know stuff after the game I need to relay to the team.
10 Reasons why Dubai sucks K Shahid's profile is simple: "I know stuff.
I know stuff I don't like and I know when it is going to sell like hotcakes.
Those close to you might commenting on just how wound up you appear, not that it's them winding you up it's just stuff, you know stuff, it's what you say when people ask what's wrong.
And once you've been in the business for a long time, people kind of know stuff about your life.