The Grammar Rule You Follow Perfectly and Could Not State

Ask a native English speaker to explain why a big red car sounds right and a red big car sounds wrong, and almost nobody can.

They will still get it right every single time.

This is the strangest thing about a first language: most of what you know about it, you cannot state. The rules were absorbed rather than taught, and they operate below the level at which you can inspect them.

Here are six of them.

1. Adjective order

English orders adjectives before a noun in a broadly fixed sequence, usually described as something like: opinion, size, physical quality, shape, age, colour, origin, material, type, purpose.

That gives a lovely little old rectangular green French silver whittling knife, which sounds tolerable. Move any two of those words and it sounds immediately wrong, in a way that is very hard to explain and impossible to ignore.

The ordering is a tendency rather than an absolute law, and it can be overridden for emphasis, but violations are noticed instantly by people who could not name a single category in the list.

2. Ablaut reduplication

When English repeats a word with a vowel change, the vowels go in a fixed order: I, then A, then O.

Hence chit-chat, ding-dong, tick-tock, ping-pong, flip-flop, sing-song, criss-cross. Reverse any of them and the result is unusable.

This rule is so reliable that it beats adjective order when the two conflict, which is the kind of detail that makes linguists happy.

3. The tag question agreement

English tag questions flip the polarity and match the auxiliary of the main clause: you are coming, aren’t you, she didn’t call, did she.

That is a genuinely complicated operation involving negation, tense and the right auxiliary, performed instantly in conversation, by everyone, including people who have never heard the word auxiliary.

4. The difference between countable and uncountable

Fewer chairs and less water, many problems and much trouble. Native speakers sort every noun in the language into one of these categories without ever being given the list, and they handle the awkward cases — two coffees, meaning two cups — without hesitation.

5. Where the stress goes

English distinguishes some noun and verb pairs by stress alone: a record against to record; a present against to present; a rebel against to rebel. The noun takes stress on the first syllable, the verb on the second.

Nobody is taught this. Everyone does it. Get it wrong and you are immediately identifiable as a learner.

6. The word that can go anywhere, except where it cannot

Expletive infixation — inserting an emphatic word inside another word, as in abso-blooming-lutely — follows strict rules about syllable stress. Speakers place it correctly without being able to say why, and misplaced examples sound wrong even though nobody has ever formulated the rule for them.

Why any of this matters

Two reasons.

The first is that it explains why learning a language as an adult is so much harder than it looks. A learner has to acquire consciously, from explicit rules and drills, what a child absorbs without instruction. The rules above are rarely in textbooks, because textbook writers are native speakers who did not know they existed either.

The second is that it should make everybody a little more relaxed about grammar arguments. The genuinely load-bearing rules of English are the ones nobody argues about, because nobody knows they are there. The rules people do argue about — split infinitives, sentences beginning with conjunctions, prepositions at the end — are mostly style preferences with a history of being invented and then enforced, and English worked perfectly well before them and will continue to afterwards.