What this is
English has one answer: the adjective goes in front. A red car, an interesting book, an old friend. French has two answers, and the default is the opposite of English — most French adjectives follow the noun.
Une voiture rouge. Un livre intéressant. Un film italien.
A small, closed set goes in front instead. It is genuinely small, it is learnable in an afternoon, and it contains most of the adjectives you already use — which is why beginners get the impression that French works like English and then produce une rouge voiture for everything else.
The rule
Default: after the noun. In particular, always after:
| category | example |
|---|---|
| colour | une robe blanche |
| nationality | un film italien |
| long adjectives | un problème important, un voisin sympathique |
| most descriptive adjectives | un sac léger, un chat mignon |
The exception set goes before. The usual memory hook is BAGS:
| adjectives | |
|---|---|
| Beauty | beau, joli |
| Age | jeune, vieux, nouveau |
| Goodness | bon, mauvais |
| Size | grand, petit, gros, long |
Une belle maison. Un vieux vélo. Un bon film. Une petite voiture.
Three of them have a third form
Beau, vieux and nouveau sit in front of the noun — which means they regularly collide with a noun beginning with a vowel. French will not tolerate the clash, so each has a special masculine form for exactly that position:
| before a consonant | before a vowel or mute h | feminine | |
|---|---|---|---|
| beautiful | un beau jardin | un bel arbre | une belle maison |
| old | un vieux vélo | un vieil ami | une vieille guitare |
| new | un nouveau professeur | un nouvel ordinateur | une nouvelle voiture |
Notice that bel, vieil and nouvel sound exactly like the feminine forms belle, vieille and nouvelle. That is not a coincidence — see below.
des becomes de in front of a preposed adjective
Des arbres → de grands arbres. Des fleurs → de jolies fleurs. When the plural indefinite article is immediately followed by an adjective, des reduces to de. Put the adjective back after the noun and des returns: des arbres magnifiques.
Why it works this way
The two positions are not arbitrary style. Broadly: an adjective after the noun distinguishes; an adjective before it does not.
Une voiture rouge picks this car out from the blue ones — the adjective is doing work, sorting the world into categories. That is why colour and nationality are always postposed: they are classifying information.
Une belle maison sorts nothing. Beauty, age, goodness and size are judgements you are bringing to the noun rather than facts that identify it, and they tend to be short, common, and already expected. French tucks those in front, out of the informational spotlight.
This also explains bel, vieil and nouvel. They exist only in the preposed slot, because only there does the adjective run straight into the noun’s opening vowel — un beau arbre would be two vowels colliding with nothing between them. French reached for a form it already had lying around: the feminine. Bel is the feminine belle with its final consonant exposed, which is exactly why they sound identical. The language solved a pronunciation problem by borrowing a form rather than inventing one.
Edge cases
The before-set is a list, not a rule
There is no test you can apply to a new adjective to decide whether it goes in front. BAGS covers the common cases, but it is a memory aid over a closed list, not a principle. When you meet an adjective you do not know, put it after the noun — that is the default and it is right far more often than not.
bel, vieil and nouvel are masculine, despite sounding feminine
Un vieil ami is a male friend. The form is borrowed from the feminine for phonetic reasons only; the article un and the gender of the noun are untouched. Writing une vieil amie is wrong twice over.
The mute h counts as a vowel here
Un bel homme, un vieil hôpital. The h is not pronounced, so the collision is real and the special form is required — the same logic that gives you l’homme rather than le homme.
des reduces only when the adjective comes first
De grands arbres, but des arbres verts. The reduction is triggered by the adjective standing between the article and the noun, not by the adjective existing. In casual speech you will hear des grands arbres; it is very common and still considered incorrect in writing.
What English speakers get wrong here
Fronting everything, because English does. Une rouge voiture, un italien film. Both are immediately wrong to a French ear in a way that is hard to un-hear.
Using beau before a vowel. Un beau arbre, un nouveau ordinateur — these are the errors the special forms exist to prevent, and they are the most common mistakes in this concept.
Assuming the special form is feminine because it sounds feminine. Vieil and nouvel are masculine forms and take un.
Keeping des in front of a preposed adjective. Des petits chiens should be de petits chiens in anything you write down.