愁 (chóu) is a common, colloquial verb meaning 'to worry about'. Unlike 发愁 (fā chóu), which is intransitive and requires a preposition like 为, 愁 can directly take an object (e.g., 愁钱). It is less formal than 忧虑 (yōu lǜ) and focuses on personal anxiety rather than the caretaking sense of 操心 (cāo xīn).