"joke"作名词时意为“笑话、玩笑”,作动词时意为“开玩笑、闹着玩”。具体如下:
名词用法:表示幽默的故事、言语或行为,旨在引人发笑。
例句:
Did I tell you the joke about the chicken crossing the road?(我跟你讲过小鸡过马路的笑话吗?)

Don't you get the joke?(你没听懂这个笑话吗?)

动词用法:指以玩笑方式表达或行为,通常带有轻松或调侃的意味。
例句:
She tied his shoelaces together for a joke.(她跟他开玩笑,把他的鞋带系在一起了。)

It's more serious than you think, so please don't joke about it.(这比你想象的严重,请不要再对此开玩笑了。)

总结:
Tell me a joke.(名词:讲个笑话。)
Stop joking!(动词:别开玩笑了!)
