French -eux and English -ous: Adjectives in Context

Learn selected -eux/-ous adjective pairs with feminine forms, meaning shifts and practical exercises.

In some useful adjectives, French -eux resembles English -ous. The pair helps with recognition, but French agreement matters when you speak or write. Learn each masculine form beside its feminine form and one natural noun phrase.

Six checked pairs with feminine forms

French masculine / feminineEnglish clueContext
dangereux / dangereusedangerousune route dangereuse
curieux / curieusecurious; sometimes strangeun enfant curieux
généreux / généreusegenerousune offre généreuse
nerveux / nerveusenervousune personne nerveuse
sérieux / sérieuseseriousun problème sérieux
mystérieux / mystérieusemysteriousune lettre mystérieuse

Five more pairs - and one meaning trap

French masculine / feminineEnglish clueContext
ambitieux / ambitieuseambitiousun projet ambitieux
religieux / religieusereligiousune cérémonie religieuse
anxieux / anxieuseanxious, worriedune attente anxieuse
précieux / précieuseprecious, valuableun temps précieux
spacieux / spacieusespaciousune salle spacieuse
gracieux / gracieusegraceful; sometimes free of chargeun geste gracieux

Gracieux is an instructive warning. It can mean graceful or gracious, while some uses mean free of charge, as in a service offered à titre gracieux. The English look-alike gracious does not cover every sense. There is also no promise that every English -ous adjective has a French -eux form.

Read Ce problème est sérieux, mais cette question est sérieuse. The English adjective stays serious; French changes with the noun. In une histoire mystérieuse, the feminine ending is -euse, not -eux. In plural, write des lettres mystérieuses.

Meaning can shift even when the pair is real

Read this connected description: L'équipe propose un projet ambitieux dans une salle spacieuse. La responsable est généreuse, mais elle reste anxieuse avant la présentation. Ses collègues prennent son inquiétude au sérieux. The masculine and feminine endings follow the nouns and people described. Prendre au sérieux is a useful phrase to learn with sérieux; the English single-word match cannot predict it.

Curieux may describe someone eager to know, but it can also mean odd: C'est une histoire curieuse. That is more likely "a strange story" than "a story that wants to learn." Généreux can describe a person's generosity or, in context, a generous amount. Keep the noun with the adjective when you study the pair.

Practice: choose and agree

  1. "A dangerous road": une route _____. Choose dangereux or dangereuse.
  2. "Serious questions": des questions _____. Write the complete adjective.
  3. In Une histoire curieuse circule dans le village, does curieuse probably mean inquisitive or strange?

Answers and why

  1. dangereuse. Route is feminine singular, so the adjective takes its feminine form.
  2. sérieuses. Questions is feminine plural: start with sérieuse and add s.
  3. Strange. A story cannot be inquisitive in this ordinary reading; the dictionary records the "odd" sense of curieux.

Production check

Write a two-sentence contrast between a spacious room and a mysterious letter. A possible answer is La salle est spacieuse. Une lettre mystérieuse est posée sur la table. Both nouns are feminine, so both adjectives end in -euse. If you change la salle to le bureau, write le bureau est spacieux.

Try making two sentences with each new adjective: one masculine noun, one feminine noun. The -ique family offers a useful comparison because many of its adjectives do not change spelling between masculine and feminine singular.

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