This meaning means to make a quick hit on something like a door to get someone's attention. People usually knock to ask permission to come inside.
He knocks on the door once.
Please knock before you enter.
This meaning is used for cars or machines when the engine makes a bad noise. It happens when the fuel burns the wrong way inside the engine.
The engine knocks when it is cold.
If you knock, check the spark plugs.
This meaning is the sound or noise made when someone knocks on something. It is often used to mean the act or event of knocking.
I heard a knock at the door.
There was a knock on the window.
This meaning is to say bad things about someone or their work. People use 'knock' to mean they do not like or respect something.
She often knocks my ideas.
Don't knock his work without proof.
This meaning means to hit or push something so it falls or moves. It can be accidental or careless.
He knocked the bike over by mistake.
She knocked the glass off the table.
This meaning is used to talk about a problem or fault in a plan, person, or thing. It means a weak point or a reason to criticize.
The only knock is the high price.
His plan has some knocks to fix.
This meaning means to hit someone or something strongly. It is often used in sports like boxing or games where you hit the ball.
He knocked his opponent out in boxing.
The player knocked the ball far away.
This meaning means to make a knocking sound to help someone wake up. People use it to get attention at a certain time.
He knocked to wake his friend up.
They knocked early in the morning.
