coal
coal — noun
1. A dark, rock-like fuel that people dig from underground. It formed over millions
A dark, rock-like fuel that people dig from underground. It formed over millions of years as ancient plants decomposed under heavy layers of earth. Setting it on fire gives off intense heat, which people use to warm buildings and generate electricity.
The power plant burns over five hundred tonnes of coal each day to keep the city's lights on.
collocation: burn coal — energy generation
Aiko picked up a dusty lump of coal from the pile and tossed it into the iron stove.
countable: a lump of coal
Generations of families in this valley have worked in the mines digging coal from deep underground tunnels.
Leila explained that burning coal releases gases which trap heat in the atmosphere and warm the planet.
The old railway line was built mainly to carry coal from the mines to the harbour for export.
- anthracite
a very hard type of coal that burns with little smoke
- coke
coal that has been heated to remove gases, used in steelmaking
- fossil fuel
broader category that includes coal, oil, and natural gas
- renewable energy
energy sources like solar or wind that do not run out
用法筆記
Usually uncountable when referring to the substance in general ('a tonne of coal,' 'coal mining'). Countable when talking about individual pieces ('a coal flew out of the fireplace').
常見錯誤
coal — verb
1. To heat wood or other plant material in an environment with little oxygen so tha
To heat wood or other plant material in an environment with little oxygen so that it turns into a black, carbon-rich substance (charcoal), often for use as fuel or in art.
The traditional method was to coal oak branches inside a clay mound for several days.
traditional craft context
Yara coaled the bamboo canes slowly over the fire pit until their surfaces turned completely black.
In rural workshops, craftsmen still coal wood in covered pits to make charcoal for blacksmith forges.
Kofi coaled the almond shells in a metal drum to make fuel for his pottery kiln.
文法句型
coal + object (wood, plant material)
用法筆記
Very rare in modern English. The verb 'char' or the phrase 'burn to charcoal' is far more common for the same meaning.
2. To provide a ship, train, or building with a supply of coal for heating or power
To provide a ship, train, or building with a supply of coal for heating or powering its engines.
The port authority coaled every transatlantic steamer before the long voyage to New York.
historical nautical context
Railway workers coaled the steam locomotives at dawn so they were ready for the morning express run.
collocation: coal + steam locomotive
During the harsh winter of 1917, the city coaled all its public schools twice as often as usual.
A team of dockworkers coaled the cargo ship before it set sail for Hong Kong.
- fuel
broader; can refer to any fuel type, not just coal
文法句型
coal + object (ship, locomotive, building)
用法筆記
Used almost exclusively in historical contexts about the age of steam. The modern equivalent is 'supply with coal' or 'fuel with coal.'
3. To take a supply of coal on board, used of a ship or steam locomotive preparing
To take a supply of coal on board, used of a ship or steam locomotive preparing for a journey.
The steamship coaled at Cape Town before continuing its journey across the Indian Ocean.
intransitive: ship + coal + at [port]
Old photographs show ocean liners coaling at Southampton harbour between transatlantic crossings.
historical context
During wartime, naval destroyers would coal quickly at secret harbours to avoid enemy submarines.
The old fishing trawler coaled every Monday at the pier before heading out to sea.
文法句型
coal + at [location]
coal + for [purpose]
用法筆記
Intransitive only — the ship or locomotive is the subject, not the person doing the supplying. Modern usage is largely limited to historical writing about the steam era.