pettier , pettiest
You can use petty to describe things such as problems, rules, or arguments that you think are unimportant or relate to unimportant things.
He was miserable all the time and fights would start over petty things.
他总是闷闷不乐,常为一些鸡毛蒜皮的事吵架。
endless rules and petty regulations.
没完没了的规则和无足轻重的规定。
If you describe someone's behaviour as petty, you mean that they care too much about small, unimportant things and perhaps that they are unnecessarily unkind.
He was petty-minded and obsessed with detail.
他谨小慎微,过于在意细节。
Petty is used of people or actions that are less important, serious, or great than others.
petty crime, such as bag-snatching and minor break-ins.
诸如抢钱包、不严重的入室盗窃之类的轻罪。