Cloud vs Fog

When to use each in English, with meaning, register, and examples.

Cloud

High-frequency chunkA2noun

Fog

Top 1,000 (very common)
 CloudFog
Pronunciation🇬🇧 /["/klaʊd/"]/🇺🇸 /["/klaʊd/"]/🇬🇧 //fɒg//🇺🇸 //fɔg//
MeaningA white or gray mass in the sky made of water or ice.A thick cloud of tiny water drops in the air that makes things hard to see.
ExampleThe sky is filled with a fluffy white cloud.The fog rolled in quickly, making the road almost invisible.
RegisterNeutralNeutral
How commonHigh-frequency chunkTop 1,000 (very common)
CEFR levelA2-
Part of speechnoun
Collocationsdense, heavy, thick, band, bank, blanket, seed, form, gather, mass, bank, cover, layer, above the clouds, below the clouds, through the clouds, a break in the cloud, a break in the clouds, great, huge, dense, create, form, belch, cloud ofheavy fog, thick fog, foggy weather, dense fog, coastal fog
Antonymssun, clear sky, brightness-
Common mistakesConfused with 'cloudy' as an adjective when describing the weather., Mispronounced as 'clowd'., Using 'cloud' as a verb incorrectly.Confused with 'smog', which is polluted fog, Using 'fog' for a light mist instead of a thick cloud, Incorrectly pluralizing 'fog' as 'fogs'
Usage notesUsed to describe the visible form of condensed water vapor in the atmosphere. Appropriate in both casual and formal contexts. Avoid using it metaphorically when talking about emotions unless discussing weather.Use 'fog' in both literal and metaphorical senses. In formal writing, avoid using 'fog' figuratively unless context allows.

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Cloud

Frequently asked questions: Cloud vs Fog

What's the difference between Cloud and Fog?

Cloud: A white or gray mass in the sky made of water or ice. Fog: A thick cloud of tiny water drops in the air that makes things hard to see.

Can you show an example of each?

Cloud: The sky is filled with a fluffy white cloud. Fog: The fog rolled in quickly, making the road almost invisible.

Can I use Cloud and Fog interchangeably?

Not always. Cloud and Fog are related and overlap in some contexts, but they differ in register, how common they are, and usage, so swapping one for another can change the meaning or tone. Check the differences above before substituting.

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