duty的用法与搭配结构

1. 表示“责任”“义务”，视含义的具体或抽象可用作可数或不可数名词。如：

Everyone has a duty to his country. 为国效劳，人人有责。

He did it out of a sense of duty. 他做此事是出于一种责任感。

表示作为工作一部分的“职责”或“职务”等，通常用复数形式。如：

Don’t forget your duties as a soldier. 不要忘记你作为一名战士的职责。

Your duties include checking the post and distributing it. 你的职责是检查和发送邮件。

2. 表示有责任或义务做某事，其后可接 to do sth 或 of doing sth。如：

A man has a duty to earn money for his family. 男人有挣钱养家的责任。

Every citizen has the duty of defending his country. 每个公民都有保卫祖国的责任。

3. 比较 do duty for sb（代替某人）与 do duty for sth（充当或当作某物用）。如：

He did duty for a sick comrade. 他接替一位患病的同志工作。

An old wooden box did duty for a table. 一个旧木箱子被当作桌子用。

4. 用于 on (off) duty, 意为“值（值）班”“当（不当）班”等（注意不用冠词）。如：

He goes on duty at 8 am and comes off duty at 5 pm. 他上午8点上班下午5点下班。

The rule is that someone must be on duty at all times. 按照规定，任何时候均需有人值班。