knock 英[nɒk] 美[nɑ:k] n. 短促的敲打(声); 爆震声; 敲击声; 敲门(或窗等)声; vi. 猛烈敲击; 与某物相撞; 撞到了桌子; vt. (心) 怦怦跳; 把…撞击成(某种状态); 批评; [例句]She went directly to Simon's apartment and knocked on the door她直奔西蒙的房间,敲了敲门.[其他] 第三人称单数:knocks 复数:knocks 现在分词:knocking过去式:knocked 过去分词:knocked

n.(名词) knock用作名词的基本意思是“狠狠的一击,打击”,用于比喻可指“不幸,挫折,艰苦”,引申可指“敲击声,敲击信号”.knock是抽象名词,但却可数,可加不定冠词修饰,也可用复数形式,表示复数概念.knock后接at〔to〕的介词短语表示侧重敲击的对象; 接on的介词短语侧重敲击的位置.v.(动词) knock的基本意思是用手、拳等硬物“敲打”,指出声地、连续地猛击,引申可指发出敲击或爆裂的声响.还可表示“批评”“数落”“非难”.knock可用作及物动词,也可用作不及物动词.用作及物动词时,可接名词或代词宾语,也可接以形容词充当补足语的复合宾语.可用于被动结构.knock是瞬间动词,如表示重复动作,须用进行体.

knock down 撞倒 knock at 敲打

knock on 撞击撞出;敲击(门、窗) knock at 敲(门、窗等) knock off 击倒;停工;中断 knock down 击倒;拆卸 knock at the door 敲门;把……撞倒;撞墙 knock out 敲空;击倒;打破;使筋疲力竭 knock it off 停止做;住口,别再讲下去了 knock on the door 敲门 knock over 打翻;撞倒 knock in (把钉子)钉入 knock on wood 敲木头,企求好运;吉人天相 knock up 敲门唤醒;[英口]筋疲力尽;往上敲

当knock off和knock over同时在表示“撞倒”意思的时候,knock over一般就是指撞倒(+ed被动),比如说A boy was knocked over by a passing car but was fortunately unhurt.而knock off则指从某个地方(被)撞倒,如A boy was knocked off his bike by a passing car but was fortunately unhurt.你是不是的做区统练上的题?

B on

两者有细微的区别: knock on 敲物体的莫个具体部位 knock at 敲物体(没有特指部位) a knock at the door中常用介词at,而不用on,因为敲门只是强调敲门这个整体,而非具体某个部位

knock into sb 撞上某人(身上) 正常不用 knock sb into还有个用法 knock sth into sth

没有不同 一个意思 he is koncking on the door he is koncking at the door

knock in to把东西敲(撞)进..,He knocked me in to the water.knock at敲打某东西,He knocked at the melon to judge if it was fully ripe.