1. I couldn't afford that big a car.
  2. It was so warm a day that I could hardly work.

The sentences stated above have been taken from Practical English Usage by Michael Swan. If I write-

  1. I couldn't afford that big car.
  2. It was so warm day that I could hardly work.

These make sense. But placement of article a makes these sentences awkward to me. Please say why and when articles are placed after adjectives. And what are the differences among 1, 2 and 3, 4.

  • english.stackexchange.com/questions/196784/…
    – Kreiri
    Commented Nov 20, 2015 at 16:19
  • 1
    @Kreiri I just read the same link. I don't think those answers answer the question. We need new answers, more grammatical, more to the point.
    – user24743
    Commented Nov 20, 2015 at 16:22
  • @Kreiri, I think Rathony is right. I also read the link. It was about such kind of problems. But it didn't show the differences in meaning among the sentences with and without article. At the same time I want to know why article is necessary after adjectives. Perhaps, this answer was available in that link. But I failed to understand. I request to the member of this site to be more specific. Thanks to all.
    – user17969
    Commented Nov 20, 2015 at 16:59
  • @Rathony Doesn't this mean that any decent answers should be merged with the original question? Site protocols still baffle me. Commented Nov 20, 2015 at 18:21
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    Sentence 4 is not grammatical. It should be: It was so warm a day that I could not work. It can be viewed as an elaboration of: It was so warm that I could not work - warm is an attribute of the verb not the noun. More information about what was so warm, modifying the predicate rather than part of the predicate or being modified by the adjective, can be added as in "a day", "a summer", "a jacket", "during the day", "on the beach", "throughout the summer", etc. Commented Nov 21, 2015 at 14:01

2 Answers 2


Short answer

If an adjective is being modified by a deictic degree adverb such as so, too, as, this or that then the adjective and adverb must go before, not after, the indefinite article. They can also appear as a postmodifier after the noun:

  • a day so warm

Full answer

There are several grammatical points about this construction. Firstly, note that the adjective precedes the article here. The adjective is modifying a whole noun phrase, not a nominal (a nominal is just the smaller phrase within a noun phrase that occurs after the determiners or articles). So we see:

  • so warm a day

and not:

  • a so warm day

Secondly you will have noticed that this adjective is itself modified by an adverb. Now this adverb must (a) be an adverb of degree and (b) must be a deictic word, in other words it is understood by reference to the immediate environment of the speaker, or through some other element of the discourse itself. Simply using a normal degree adverb will not work here:

  • *He was very good a footballer as ...
  • *He was extremely good a footballer that ...

The adverbs that can be used like this are so, too, as, this, that as well as how. Some grammarians have also included more, less and enough in this list, but the grammar of these adverbs is in fact significantly different. Notice that this and that are adverbs here, not determiners.

The adverbs so, too, as, how, this, that and how are degree adverbs that cannot themselves give us any idea of actual degree or extent involved. We could think of them as a kind of 'pro - degree adverb'. These adverbs require some kind of benchmark for us to appreciate the actual degree involved. If this information is not provided by the context this normally entails there being a Complement phrase which indicates the actual extent or degree involved. We can consider such sentences in this way:

  • It was (X)big a problem [that we gave up the whole project]

Here (X) represents the degree involved. On its own (X) does not tell us the actual degree of the bigness of the problem. It is the clause in brackets which explains the actual extent of the size of the problem.

The adverb involved will dictate what kind of phrase or clause can function as the Complement. The adverb so can take preposition phrases headed by the preposition as or finite clauses typically using the subordinator that. In the sentence above the only possible adverb we could use instead of (X) is the adverb so.

The adverb as typically takes phrases headed by as. It cannot take clauses headed by that.

The adverb too takes to-infinitival clauses, headed by for if they include a Subject:

  • He was so big an idiot [that he wasn't allowed to speak in public without his advisors].
  • It was so forceful a blow [as to fell his opponent].
  • He is as great an actor [as has ever graced this stage].
  • He is as good a footballer [as the next]'
  • He was too valuable an asset [to let go].
  • It was too dangerous a project [for us to take it on].

The preposition as (as opposed to the degree adverb) introduces equality with what follows it. More precisely it indicates some kind of benchmark which is met or exceeded.

Notice that the deictic degree adverbs this, that and how usually don't require a following phrase to provide the benchmark. It is normally clear from the discourse itself. However that sometimes takes finite clauses with that to provide a benchmark when it isn't available from the discourse:

  • It was that big [that I couldn't fit it through the door].

Lastly, when how is interrogative as opposed to exclamative then it is not deictic - in the sense that the degree expressed is left unresolved and in direct questions may be expected to be supplied by the respondent:

  • I wondered how long a journey it actually was.
  • How long a rope do we need?

Notice that we cannot generally put adjectives before articles, the following are badly formed:

  • *big a footballer
  • *clever an idea

This only occurs when the adjective is being modified by a deictic degree adverb. Why? I don't know. I've been looking into this for quite a long time but haven't been able to find out.

The Original Poster's Examples:

Sentences (1) and (2) are grammatical. Sentence (3) is also grammatical, but this is because the adjective big is not being modified by any adverb. The word that here is a Determiner. Sentence (4) is completely ungrammatical. Because day is singular we must use a Determiner here. If we used an indefinite article then because warm is being modified by a deictic degree adverb, the adverb adjective combination should precede the article - as in sentence (2).

Note: Thanks to Edwin and fdb for helpful observations, which have been edited into the answer.

  • I always believed it has something to do with etymology that has nothing to do with the grammar that we know of at this moment. It might be impossible to explain this other than "that's the way it is".
    – user24743
    Commented Nov 20, 2015 at 16:56
  • @Rathony Yes, I agree. Commented Nov 20, 2015 at 16:58
  • "If an adjective is being modified by a deictic degree adverb such as so, too, as, this or that then the adjective and adverb must both come before the indefinite article." This "rule" is blatantly wrong. It is perfectly correct to say "I could not afford to buy a car that big".
    – fdb
    Commented Nov 20, 2015 at 17:11
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    @Araucaria I confess, it was from the Cobuild book on articles rather than immediately available in my mind-storage–depot. Commented Nov 21, 2015 at 13:57
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    @DavidMWPowers There is a view that noun phrases with adjectives are in fact adjective phrases, not noun phrases at all. That would fit in with your view. However, the idea that how big a bag is modifying the Predicate in how big a bag did you buy is a bit strange. After all it is the Direct Object of the verb buy and therefore - by definition - a Complement of the verb and not a Modifier in the verb phrase. But it's an interesting point. Commented Nov 21, 2015 at 14:35

Regarding example (1), I think the emphasis of "that big a car" considerably differs from "that big car." "That big a car" could be rephrased as a "a car as big as that," which shows that you are comparing the car in question to some standard of a car that you have in your mind. "That big car" on the other hand seems to solely indicate that you're just pointing to a car that's right there, in person, in a magazine, whatever. Regarding (2) I'm not sure whether there's an issue -- or at least your example (4) is ungrammatical in English. You would need some sort of article before "day," so as it stands number (2) is the only acceptable of the two ways to express that thought (there could be others of course, but I haven't thought of them).

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