hit 表示“有目标地打”，着重“打击”某一点。也有“袭击”之意。
He hit him on the face．他打了他的脸。
One of the stones hit the window. 有一块石头打中了窗户。
An earthquake hit the district. 这个地区受到了地震的袭击。
strike 指有意识的动作，也可以指无意识的动作，通常指一下一下地打或敲击，也可能用力地打一下。敲钟必须用strike。
Strike while the iron is hot. 趁热打铁。
The clock is striking 12. 钟在敲12点。
beat 指有目的地在某物上连续不断地击打、轻打、重打都可以。有“殴打、击败”之意。
That man was beaten until he was black and blue．那个人被打得青一块、紫一块。
The Iraq army was beaten. 伊拉克军队被打败了。
He could feel his heart beating fast．他能感到他的心跳快。
knock 指敲打并伴有响声，常与at／on连用。它还有“打倒、打翻”的意思。
Someone is knocking at the door. 有人敲门。
He knocked the girl down. 他把那个女孩撞倒了
