nag

Compared meaning: to express dissatisfaction (verb).

比较义项：抱怨，表达不满（动词）。

• complain

  Neutral verb for expressing dissatisfaction, once or repeatedly, to anyone; often followed by 'about' or 'that'; no strong negative judgment of the speaker.

  中性动词，表示向任何人表达不满，可以是一次性的，也可以是反复的；常与“about”或“that”连用；不带有对说话者的强烈负面评价。

  She complained to the manager about the slow service at the restaurant.

  她向经理抱怨餐厅服务太慢。

• nag 本词

  Negative, informal verb for repeatedly complaining to or pestering a specific person about the same small thing, seen as annoying; often used between family members.

  带贬义、非正式的动词，指反复就同一件小事唠叨或催促某个特定的人，会让人觉得烦；常用于家人之间。

  His wife keeps nagging him to fix the leaking tap.

  他妻子一直唠叨他去修那个漏水的水龙头。

Complain and nag both mean to express dissatisfaction. Complain is neutral: expressing dissatisfaction, once or repeatedly, to anyone, often with 'about' or 'that'. Nag is negative and informal: repeatedly complaining to or pestering one specific person, usually a family member, about the same small thing.

两者都表示因不满而说出来，但 complain 是中性词，指一般性地表达不满，可以是对朋友、店员或任何人一次性地抱怨；nag 带贬义，指反复、唠叨式地催促或抱怨同一件事，通常针对熟悉的人（如家人），令人厌烦。