He was miserable all the time and fights would start over petty things.

他一直都很闷闷不乐，常为一些鸡毛蒜皮的事吵架。

《柯林斯英汉双解大词典》

It's little petty things like this.

就是这样的小玩意儿。

youdao

Don't bother me with such petty things.

不要用这种小事情烦我。

youdao

exhibits a sort of lofty detachment to the more or less petty things that weigh most of us down.

这类人展现了一种,对琐碎事物的崇高超脱,让我们大多数人无地自容。

耶鲁公开课 - 政治哲学导论课程节选

There's not enough information, they throw very small, petty things back at you that are almost insignificant.

BBC: HS2 compensation: Government spends ?43m on 72 properties

She asked those of us in Washington to get past our petty grievances and make things right.

WHITEHOUSE: President Obama's Statement on the Budget Agreement

And a lot of the things that seem important, the petty differences melt away, and we focus on what binds us together and that we as Americans are going to stand with each other in their hour of need.

WHITEHOUSE: President Obama Tours Storm Damage in New York City