Tāmen zǒngshì wèi yīxiē jīmáo-suànpí de shì zhēngchǎo.
They always argue over petty, insignificant things.
Tips
usage
鸡毛蒜皮 (chicken feathers and garlic skins) is a common four-character idiom meaning utterly trivial or petty. 鸡毛 alone can modify nouns: 鸡毛小事 (petty little thing). Historically, innkeepers used chicken feathers as cheap bedding, the 鸡毛店.
