complain音标为 kəmˈpleɪn，中文意思是抱怨、诉苦、投诉。它指对不满情绪或问题的口头表达，常用于描述因不适、烦恼或不公而发出牢骚。

complain的用法分为不及物和及物动词两种。作为不及物动词时，后常接介词about或of，complain about表示对一般事物抱怨，complain of则多指诉说病痛或身体不适；作为及物动词时，后接that引导的宾语从句，直接陈述抱怨内容。

以下是10个带中文翻译的例句：

1 Many customers complain about the poor service here
许多顾客抱怨这里的服务差

2 She often complains of headaches after long work
她经常诉说长时间工作后头痛

3 He complained that the room was too noisy to sleep
他抱怨房间太吵无法入睡

4 If the food is cold you should complain to the manager
如果食物是冷的你应该向经理投诉

5 Neighbours complained about the loud music last night
邻居们投诉昨晚音乐声太大

6 The patient complained of chest pain this morning
病人今早诉说胸部疼痛

7 You have no reason to complain about your salary
你没有理由抱怨你的薪水

8 They complained that the bus was always late
他们抱怨公交车总是晚点

9 She never complains despite her difficulties
尽管困难重重她从不诉苦

10 He complained to the police about the neighbourhood noise
他向警方投诉了社区的噪音问题

常见短语搭配包括：

complain about sth 抱怨某事
complain to sb 向某人投诉
complain of pain 诉说疼痛
complain bitterly 强烈抱怨
constantly complain 不断抱怨
right to complain 投诉权利
complain formally 正式投诉
complain loudly 大声抱怨