The phrase "a petty thing" is correct and usable in written English.
It can be used to describe something that is trivial, insignificant, or of little importance.
Example: "I realized that arguing over the color of the curtains was just a petty thing in the grand scheme of our relationship."
Alternatives: "a trivial matter" or "a minor issue".
"The girl not allowed to wear the kara is a petty thing for the administrators to have done and it doesn't do them any good," Singh said.
"If I look for the positive side, though, when she goes upstairs, her parents often say that what she is quarreling about is a petty thing, and she will come back down and maybe the whole thing will be forgotten".
A small advantage to this is perhaps a petty thing, but nothing drives a mean person nuts more than not getting a rise out of you.
It's such a petty thing to take someone to court, but they've done us a favour by doing so, given how much attention the cause has had".
Because that's what you're going to be if you try to correct your boss about a petty thing like getting your name wrong".
The simple reality is that you are living in a society where how you look matters, and for the person who is down and out, this can seem like a petty thing to concern yourself with.
If someone unjustly blamed me for any petty thing that went awry, the blame was duly delivered to its rightful owner.
Distractions aside, Kucinich was our early favorite for this week's MDDOTW, but in the end we decided not to be petty -- even though we could do so to make a point (for someone of Dennis Kucinich's stature, filing such a lawsuit was a pretty petty thing to do), we're not going to.
Like so many chores that get done around the house, it lies in that category of work that needs to be started almost as soon as it has been completed, coming at us with a ruthlessness typical of all petty things; it's done only to become undone, then done again.
"I think this is just a very, very petty thing to do.
"It brings the whole team together, so any little niggles that are happening, any petty things that are happening within the staff, you find after a laughter workshop they're dissipated and of course you're more relaxed and you're more creative".
