Irregular Adjectives

French irregular adjectives
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Adjectifs irréguliers

Five French adjectives are particularly tricky for several reasons.

  1. They are among the relatively few adjectives that precede nouns.
  2. They have very irregular feminine forms.
  3. They have three masculine forms.
Singular   Plural
Masc Special Fem   Masc Fem
beau bel belle   beaux belles
fou fol folle   fous folles
mou mol molle   mous molles
nouveau nouvel nouvelle   nouveaux nouvelles
vieux vieil vieille   vieux vieilles

As you can see, in addition to the usual four adjective forms required to agree with nouns in gender and number, there is a special fifth form that is used only with masculine singular nouns that begin with a vowel or mute h.

Par exemple …

un beau pays   un bel endroit
un fou rire   un fol héroïsme
un mou refus   un mol effort
un nouveau mois   un nouvel an
un vieux monsieur   un vieil homme


  • The special masculine form is required for euphony.
  • It’s pronounced just like the feminine adjective.
  • There is no special form for plural nouns.

Par exemple …

plusieurs beaux endroits
trois vieux hommes

 Irregular Adjectives Quiz

Think you’ve got it? Test yourself on agreement with beau, nouveau, and vieux with this fill-in-the-blanks exercise: Promenade en forêt

Note: You must be logged into your Progress with Lawless French account to take this test. If you don’t have one, sign up – it’s free!

Expressions with bel

Bel is also found in two fixed expressions:

  • bel et bien – well and truly, really, undoubtedly
  • tout cela est bel et bon (mais…) – that’s all well and good (but …)

 Related lessons

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Beau, fou, mou, nouveau, vieux

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