My kid saw the scene and told me,

There is a fog.

enter image description here

Do we use "a" before fog?

  • 5
    I think you could use both: "There's fog out there." "There's a thick fog rolling in." By itself, it sounds better to say, "There's fog," since your son is not talking about a specific type of fog, i.e. thick, thin, low, etc. Your son's statement is not countable either whereas the one with "thick" in it is technically countable.
    – Nick
    Commented Dec 28, 2017 at 6:39

3 Answers 3


In this context, no, there shouldn't be an article. That said,

There is fog

However, 'a fog' is possible but in different context.

This problem has me in a fog.

Or, if you want to say some type of fog or emphasize the intensity.

A blanket of fog covered the fields.

If you are still confused, open up any authentic dictionary (OALD, for example) and check whether the noun is countable or uncountable. Further, check that in which sense it is countable studying some examples.


As in the comment by Livrecache, I came across examples from books and other reliable sources that wrote 'a fog' as well. So, it's not completely wrong!

  • 1
    I agree with the answer provided, but one could say "A fog lies over London" without any qualifiers. And one would not be queried on "There is a mist." I think the way your son expressed himself is rather nice. English is such a flexible language!
    – Livrecache
    Commented Dec 28, 2017 at 6:50
  • 1
    @Livrecache Oh yes, I checked...and edited the answer accordingly. Thank you! :)
    – Maulik V
    Commented Dec 28, 2017 at 7:24
  • 3
    I wouldn't call it wrong at all. Using a with fog is quite idiomatic.
    – J.R.
    Commented Dec 28, 2017 at 10:49

Your child's sentence is correct.

The word fog is much like the word rain, in that an article can either be included or omitted in many contexts. All of these sentences are grammatically correct:

  • Thick fog rolled in just after sunset.

  • A thick fog rolled in just after sunset.

  • Just after nine o'clock, heavy rain fell.

  • Just after nine o'clock, a heavy rain fell.

If you check the Ngram for "when thick fog" vs. "when a thick fog", you'll see that both expressions are used. Some examples:

We had just time to anchor, in a complete calm, when thick fog set in once more. (Source)

The fishermen had been hauling trawl lines into the dory when a thick fog rolled in, obscuring their view of the schooner. (Source)

  • 2
    The OP's sentence doesn't contain the adjective "thick", so your examples, which are all helpful and correct, are nevertheless biased. To my ears Avoid driving because of fog sounds more idiomatic than Avoid driving because of a fog Now, why is that?
    – Mari-Lou A
    Commented Dec 28, 2017 at 12:20
  • 1
    Likewise "rain" by itself is not usually countable: "Rain poured down" not "A rain poured down" or "Rains poured down" The first sentence is idiomatic.
    – Mari-Lou A
    Commented Dec 28, 2017 at 12:24
  • @Mari-Lou - No adjective is needed. A fog settled in is just fine. As for your preposition, Avoid driving in fog and Avoid driving in a fog are both fine; I think it's the "because of" that makes one sound off.
    – J.R.
    Commented Dec 28, 2017 at 12:39
  • 1
    @Mari-LouA - They may not be "exactly the same," but, you must admit, "There is a fog" is about as stark a sentence as one could conjure. I was trying to use something a bit more vivid. In any case, whether the sentence is more descriptive (such as McCullough's, The fog lost its density. A thin vapor seemed to rise from it – a fog upon a fog – like a mist from the ocean, and the whole began to settle and to melt away.), or bare-bones (I see a fog, e.g.), my bottom-line answer is the same: You can include an article, or omit it.
    – J.R.
    Commented Dec 28, 2017 at 14:44
  • 2
    And my objection remains the same, none of your examples contain the bare sentence. Agreed, "thick" and "dense" and "blanket" and "patch" help make the word fog all the more interesting but the OP doesn't care about that (if they do, they haven't said so). They want to know if "There is a fog" is grammatically correct because their child uttered this phrase. The Q is not how to make the sentence more evocative. You still haven't said anything about "A rain fell" or "A rain poured down", are these examples grammatical without the heavy that qualifies it? [wink]
    – Mari-Lou A
    Commented Dec 28, 2017 at 15:05
  1. There is a fog.
  2. There is some fog.
  3. There is fog.

All of the above are grammatical, although "fog" is something which you do not normally quantify. We don't normally say “There are some fogs.” Instead, we would use another word in front which is countable. For example, patch.

There are some patches of fog.

If the fog is extensive and covers a wide area, the term blanket may be used.

The hills were covered by a blanket of fog

I believe that sentence 1 is a type of ellipses for

  1. There is a [patch of] OR [blanket of] fog.

What do the dictionaries say?

Macmillan Dictionary says


1 [COUNTABLE/UNCOUNTABLE] a thick cloud that forms close to the ground or to water and is difficult to see through.

2 [SINGULAR] a cloud of smoke or some other gas
fog of: a fog of cigar smoke

Oxford Living Dictionaries say


  1. mass noun
    A thick cloud of tiny water droplets suspended in the atmosphere at or near the earth's surface which obscures or restricts visibility (to a greater extent than mist; strictly, reducing visibility to below 1 km)

    • ‘Your Jeep fog lights can help you cut through thick fog or rain with ease and without temporarily blinding your eyes.’

1.1 in singular
An opaque mass of particles in the air.

  • ‘The cloud clearly isn't steam in the strict sense, nor vapour (these are both invisible) but a fog of small ice crystals.’

Interestingly, Cambridge Dictionary does not acknowledge the singular form in British English, it defines it as being uncountable


A2 [ U ] a weather condition in which very small drops of water come together to form a thick cloud close to the land or seaocean, making it difficult to see:

  • Thick/Heavy/Dense fog has made driving conditions dangerous.
  • Mist, fog, and snow are common in this area.
  • It took several hours for the fog to lift.

But in American English, fog is countable and uncountable. Unfortunately, the only example provided is the uncountable sense.

noun [ C/U ] US
[ U ] Heavy fog made driving conditions dangerous.

Longman Dictionary goes into some detail. To summarize, it describes fog as being both COUNTABLE and UNCOUNTABLE (mass noun)

  • It will be a cold night, and there may be fog patches
  • A blanket of fog covered the fields.

And lists the following phrases

a blanket of fog (=a large area of fog)
A blanket of fog lay over the town.

a bank of fog (also a fog bank) (=a large mass of fog)
As we approached the coast, we ran into a dense bank of fog.

patches of fog (=fog that forms in some places but not in others)
Patches of fog are expected later today.

  • If I have made some mistake, I'd appreciate hearing about it. Thanks.
    – Mari-Lou A
    Commented Dec 28, 2017 at 19:09

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