1 A2 neutral
To rap on a door or surface with the knuckles to attract attention or request entry.
"She knocked on the office door twice and waited for an answer before entering."
inseparable
knock on
A2 neutral inseparable transitive
To strike a door or surface with the knuckles to signal your presence or to gain entry.
In plain English
To tap or hit a door to let people know you are there.
What does "knock on" mean?
2 meanings, ordered from most common to least. Color-coded by CEFR level.
2 B1 idiomatic informal
In the phrase 'knock on wood': to touch wood as a superstitious gesture to avoid bad luck after saying something optimistic.
"We've had no accidents this year — knock on wood."
Literal vs figurative
Words literally mean
To strike your knuckles on a surface.
Actually means
To tap or hit a door to let people know you are there.
Usage tip
Primarily literal. 'Knock on wood' (North American) or 'touch wood' (British) is a separate fixed phrase meant to ward off bad luck. The adjective 'knock-on' (as in 'knock-on effect') is derived from the same base and means an indirect consequence. Rugby also uses 'knock-on' as a technical foul.
Words that pair with "knock on"
Natural word combinations native speakers use most often.
door wood window wall table effect
How to conjugate "knock on"
The five tense forms you'll use most often.
Base
knock on
I/you/we/they
3rd person
knocks on
he/she/it
Past simple
knocked on
yesterday
Past participle
knocked on
have + pp
-ing form
knocking on
continuous
Hear "knock on" in the wild
Listen to native speakers using "knock on" in real YouTube videos — click a clip to watch it on Looplines.
Other ways to say "knock on"
Swap in when you want variety — tap a linked one to explore it.
Keep exploring
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