进别人家门或者房间之前先敲门，是有礼貌的表现。那么，“敲门”用英语怎么说呢？有些朋友可能会想到“knock the door”，但是它怎么说呢，有点简单粗暴，更像是“破门而入”。
knock the door 破门而入“knock”做及物动词后面直接跟物的时候表示“碰，撞；碰倒；撞倒”。“knock the door”更多有撞门的意思。She knocked her head against the wall as she fell.她跌倒时头撞在墙上。“knock”也可以做不及物动词，表示（反复地）敲，击，打。如果我们想要说“敲门”，可以在中间加上“at”或者“on”。knock at/on the door 敲门There's someone knocking on/at the door.有人在敲门。如果前面加上“the”变成一个名词短语，就有“警察（或士兵）到家里来把某人带走”的意思。During the dictatorship people had come to fear the knock at the door in the middle of the night.独裁时期，人们害怕半夜时会被人从家里抓走。所以其实更建议直接说“knock knock”，美剧里这种表达也很多，大家都能理解是敲门的意思。Please knock before entering.进来前请先敲门。
“knock”在英语里很常见，有很多相关的短语表达，一起来了解一下吧。be knocking (on) 60, 70, etc. 快60/70岁等（通常指高龄）She was knocking on 80 when she died.她去世时快80岁了。knock (some) sense into sb 让（某人）懂道理A couple of years in the army will knock some sense into him.当几年兵会让他懂些道理。knock on wood 老天保佑The deal will be agreed on Wednesday, knock on wood.这笔交易将在星期三达成，老天保佑。
knock it off 住嘴；住手Oh, knock it off Alex, I'm really not in the mood for your jokes.哎，别说了，亚历克斯，我真的没心情听你说笑话。