La place et l'accord des adjectifs
Two questions every time you use an adjective in French. Where does it go — before or after the noun? And what form does it take — masculine, feminine, singular, plural? The default placement is AFTER the noun (un livre intéressant), but a small group of common adjectives goes BEFORE (un beau livre). And almost every adjective changes its ending to match its noun.
Default placement: after the noun
Most French adjectives — color, shape, nationality, anything descriptive that's longer than two syllables — sit AFTER the noun. un livre intéressant (an interesting book), une voiture rouge (a red car), un homme français (a French man), une fille intelligente (a smart girl). This is the opposite of English, which puts adjectives before. Get used to it: noun first, then the adjective.
BAGS — the adjectives that go BEFORE
A short list goes in front. Memorize them as B-A-G-S: Beauty, Age, Goodness, Size. Beauty: beau / belle (beautiful), joli / jolie (pretty). Age: vieux / vieille (old), jeune (young), nouveau / nouvelle (new). Goodness: bon / bonne (good), mauvais / mauvaise (bad). Size: grand / grande (big, tall), petit / petite (little), gros / grosse (fat, large). So: un beau livre, une vieille maison, un bon café, une grande ville.
Agreement: feminine adds -e
Most adjectives add -e for the feminine. petit → petite, grand → grande, français → française, intéressant → intéressante, content → contente. The added -e wakes up the silent final consonant: petit sounds 'puh-TEE' but petite sounds 'puh-TEET'. Adjectives already ending in -e don't change: jeune, rouge, simple, facile, difficile are the same in masculine and feminine. Un livre rouge / une voiture rouge.
Plural: add -s (mostly silent)
Add -s for plural — but it's silent in speech, so plural sounds identical to singular: petit / petits, petite / petites. The four forms: un petit livre, une petite maison, deux petits livres, deux petites maisons. Adjectives already ending in -s or -x don't add another: français / français (m. pl.), vieux / vieux. Final -al changes to -aux: un problème national → des problèmes nationaux.
Common irregular feminines
Some adjectives have a special feminine form — memorize each as a pair. bon → bonne (double n). gros → grosse. gentil → gentille. blanc → blanche. heureux → heureuse (the x turns into se). vieux → vieille. beau → belle. nouveau → nouvelle. fou (crazy) → folle. The pattern is unpredictable, so just learn them as units: un beau garçon / une belle fille, un nouveau livre / une nouvelle voiture.
beau / nouveau / vieux before a vowel
Three of the BAGS adjectives have a third form, used only before a masculine singular noun starting with a vowel: beau → bel, nouveau → nouvel, vieux → vieil. un bel homme (a handsome man — not 'un beau homme'), un nouvel ami (a new friend — masc.), un vieil ami (an old friend). Pronunciation reason — French hates two vowels colliding. The feminine forms (belle, nouvelle, vieille) already sound fine and don't need this trick.
