duty这个单词是名词，意思是“责任; 值班; 职责; 任务”等。短语off duty的意思是“下班，不值勤”的意思。例句如：
What time do you go off duty?
你什么时候下班？
They clocked off duty and left at ten to three.
他们打卡下班，于2点50分离开。
Four officers were told to go off duty and rest at home
四名官员已经被通知停职在家休整。
She is off duty now.
她已经下班了。
Come and visit us when you're off duty.
下班后请来看我们。
Only the nurse is on duty, all the others are off duty today.
今天只有一个护士值班，其他人都不值班。
