knocking
knocking — verb
1. to hit a door, window, or other surface with your hand, a tool, or a hard object
to hit a door, window, or other surface with your hand, a tool, or a hard object, usually to get someone's attention or to show that you are there.
Gabriel knocked on the classroom door before entering.
knock + on + door + before entering
The postman knocked three times, then left a parcel on the step.
knock + number of times for attention
Ayesha heard someone knocking at the window and looked up from her book.
Otis knocked loudly on the old wooden door, but nobody answered.
The children knocked on every door in the street to collect money for charity.
文法句型
knock + on/at + noun
用法筆記
The surface being hit is introduced by 'on' (most common in British English) or 'at' (more common in American English). This sense does not take a direct object — you knock on a door, not knock a door.
常見錯誤
2. to hit someone or something with enough force that they fall to the ground, move
to hit someone or something with enough force that they fall to the ground, move aside, or are sent in a particular direction.
Darius accidentally knocked over a glass of water while reaching for his keys.
knock + over + glass — accidental
The strong wind knocked the garden chairs onto the grass.
wind + knocked + chairs — inanimate subject
Chidi's bicycle hit a stone and knocked him off the seat.
Apinya knocked the vase off the shelf while dusting the living room.
A cyclist knocked over an elderly pedestrian at the crossroads yesterday.
文法句型
knock + object + over/off/down
用法筆記
Nearly always used with a particle (over, off, down, aside) that tells you the result of the impact. Without the particle, the meaning changes to sense 1 (HIT SURFACE). The object must be stated — you knock something over, not just knock over.
常見錯誤
❌ 'I knocked the glass over when I bumped the table.' (correct as is) — This is the correct structure. The mistake is often dropping the particle: ❌ 'I knocked the glass.' (sounds like sense 1 — hitting it, not causing it to fall).
3. to say critical or disapproving things about someone or something, often in a wa
to say critical or disapproving things about someone or something, often in a way that seems unfair or unnecessarily negative.
Paloma criticised the plan, but her boss told her to stop knocking it.
stop + knocking — informal pattern for 'stop criticising unfairly'
The newspaper keeps knocking the government's education policies.
keeps + knocking — repeated criticism, informal
Some reviewers are always knocking this director, but audiences love his films.
Instead of knocking your teammates, try giving them helpful advice.
Tunde's friends keep knocking his taste in music, which he finds annoying.
- praise
to express approval or admiration
- compliment
to say something positive about someone
文法句型
knock + noun phrase (person/thing/idea)
用法筆記
Informal register. Stronger and more dismissive than 'criticise'. Often implies the criticism is habitual, petty, or undeserved. Common in phrases like 'stop knocking [sb/sth]' and 'always knocking [sb/sth]'. Less common in formal writing.
常見錯誤
4. to remove a wall or partition that separates two rooms, joining them together to
to remove a wall or partition that separates two rooms, joining them together to create a single larger living space.
The couple decided to knock through the wall between the kitchen and the dining room.
knock + through + wall — phrasal verb pattern
Harper knocked the two small bedrooms into one to make a larger space.
knock + [room] + into + [room] — combining rooms
A structural engineer checked the wall before they could knock through.
Some old houses have thick walls that are expensive to knock through safely.
The homeowners knocked the living room into the kitchen to create an open-plan area.
文法句型
knock + through + wall
knock + room + into + room
用法筆記
Chiefly British English. Very common in home renovation contexts. The wall must be checked by a professional because some walls are 'load-bearing' — knocking them out without support can cause the building to collapse. Usually used with 'through' or the pattern 'knock X into Y'.
常見錯誤
5. (of a car or other vehicle engine) to make a sharp repeating sound when the fuel
(of a car or other vehicle engine) to make a sharp repeating sound when the fuel-air mixture burns unevenly or when a mechanical part works loose, signalling a fault that needs repair.
The car engine started knocking, so Vinícius drove it straight to the garage.
engine + started knocking → needs repair
Using low-quality fuel can cause an older engine to knock badly.
fuel quality + cause + engine to knock
The mechanic said the knocking sound meant the pistons needed replacing.
Adaeze heard a loud knock from the engine and immediately pulled over to the side.
If your car engine is knocking, you should not drive it for a long time.
文法句型
engine + is knocking
start + knocking
用法筆記
Used in automotive contexts. The verb is most common in continuous tenses ('the engine is knocking'). Engine knock is also called 'pinking' or 'detonation'. This is distinct from the normal sound of a running engine.
常見錯誤
6. (of a household pipe, radiator, or boiler) to make a regular banging or tapping
(of a household pipe, radiator, or boiler) to make a regular banging or tapping sound as water or steam flows through it, often caused by trapped air, loose fittings, or changes in temperature.
The radiator knocks every time the central heating comes on.
radiator + knocks + when heating starts
Élise called the plumber because the pipe in the bathroom was knocking all night.
pipe + was knocking + calls plumber — repair needed
The knocking from the old water pipes kept the whole house awake.
After the plumber removed the trapped air, the pipes stopped knocking completely.
A loud knocking in the boiler usually means it needs immediate attention.
文法句型
pipe + is knocking
knocking + in + pipe/radiator
用法筆記
Common in British English for describing plumbing issues. The knocking is often called 'water hammer' in technical terms. Differs from sense 5 (ENGINE NOISE) in that the source is household plumbing, not a vehicle engine.