關於duty的用法與搭配結構

　　1. 表示有責任或義務做某事，其後可接 to do sth 或 of doing sth。如：

A man has a duty to earn money for his family. 男人有掙錢養家的責任。

Every citizen has the duty of defending his country. 每個公民都有保衛祖國的責任。

　　2. 表示“責任”“義務”，視含義的具體或抽象可用作可數或不可數名詞。如：

Everyone has a duty to his country. 爲國效勞，人人有責。

He did it out of a sense of duty. 他做此事是出於一種責任感。

表示作爲工作一部分的“職責”或“職務”等，通常用複數形式。如：

Don’t forget your duties as a soldier. 不要忘記你作爲一名戰士的職責。

Your duties include checking the post and distributing it. 你的職責是檢查和發送郵件。

　　3. 比較 do duty for sb(代替某人)與 do duty for sth(充當或當作某物用)。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. 一箇舊木箱子被當作桌子用。

　　4. 用於 on (off) duty, 意爲“值(值)班”“當(不當)班”等(注意不用冠詞)。如：

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

The rule is that someone must be on duty at all times. 按照規定，任何時候均需有人值班。