v.敲击；互撞；攻击
n.敲；敲门；敲打
Someone is knocking at the door. 有人在敲门。
One may knock to signal one's presence to others. 可以用敲击发出的声音向别人表明自己的存在。
He knocked a big hole in the wall. 他把墙撞出了一个大洞。
I am so hurried as to knock into my teacher. 我如此匆忙以至于撞到老师身上。
The man is knock down by the bicycle. 这个男人被自行车撞倒了。
用作名词 (n.)There was a knock at the window. 有人敲了一下窗户。
I heard footsteps, then a knock on the door. 我听到脚步声，随后是敲门的声音。
There was no answer to my knock, so I went away. 我敲门没人应，所以就走开了。
She took a bad knock when her husband died. 丈夫的死,使她受到沉重的打击。
When I fall, I get a terrible knock on the head. 我摔倒时头撞得很厉害。
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。
下面两个句子意思相同: He is knocking at the door.He is knocking on the door.他在敲门。
