v. express complaints, discontent, displeasure, or unhappiness
v. make a formal accusation; bring a formal charge
v. 抱怨, 抗议, 控诉
1. I want to complain about the poor service at the restaurant.
我想投诉餐厅的服务很差。
2. She always complains when the weather is too hot.
她总是在天气太热的时候抱怨。
3. If you are not happy with the product, you should complain to the store.
如果你对产品不满意，应该向商店投诉。