Irregular Adjective Agreements
Some adjectives don't just add -e for feminine — they transform entirely
Category: Gendered Nouns
The Rule
Common irregular patterns: -eux→-euse, -er→-ère, -f→-ve, -el→-elle, and fully irregular forms like beau/belle, nouveau/nouvelle, vieux/vieille.
Why This Matters
While most adjectives follow the regular 'add -e' rule, many high-frequency adjectives have irregular feminine forms. English speakers must memorize these because they appear in everyday conversation constantly. The three most important irregular adjectives — beau, nouveau, vieux — also have special forms (bel, nouvel, vieil) before masculine nouns starting with a vowel.
Examples
• Un homme heureux / Une femme heureuse — "A happy man / A happy woman" [-eux → -euse] • Le premier jour / La première nuit — "The first day / The first night" [-er → -ère] • Un garçon sportif / Une fille sportive — "A sporty boy / A sporty girl" [-f → -ve] • Un beau château / Une belle maison — "A beautiful castle / A beautiful house" [beau → belle (fully irregular)] • Un vieil arbre / Un vieux pont — "An old tree / An old bridge" [vieil before vowel, vieux before consonant]
Common Mistakes
❌ Elle est heureuse? Non, elle est heureux. ✅ Elle est heureuse. → Heureux becomes heureuse for feminine, not the other way around. ❌ Une beau robe. ✅ Une belle robe. → Robe is feminine — use belle, not beau. ❌ Un beau arbre. ✅ Un bel arbre. → Before a masculine noun starting with a vowel, beau becomes bel.
Quick Tip
Memorize beau/bel/belle, nouveau/nouvel/nouvelle, vieux/vieil/vieille as a set. They follow the same three-form pattern.
Memorize beau/bel/belle, nouveau/nouvel/nouvelle, vieux/vieil/vieille as a set. They follow the same three-form pattern.
Examples
Common Mistakes
Incorrect: Elle est heureuse? Non, elle est heureux. → Correct: Elle est heureuse.. Heureux becomes heureuse for feminine, not the other way around.
Incorrect: Une beau robe. → Correct: Une belle robe.. Robe is feminine — use belle, not beau.
Incorrect: Un beau arbre. → Correct: Un bel arbre.. Before a masculine noun starting with a vowel, beau becomes bel.
Quiz
What is the feminine form of 'nouveau'?