-ous becomes -eux
Many English adjectives ending in -ous have French equivalents ending in -eux. This pattern is especially useful because many of these words come from related Latin roots.
Common examples include dangerous and dangereux, curious and curieux, and serious and sérieux.
The pattern is common, but it is not automatic. Some English words ending in -ous have different French equivalents.
The basic pattern
A large number of English adjectives ending in -ous correspond to French adjectives ending in -eux.
| English | French |
|---|---|
| adventurous | aventureux |
| ambitious | ambitieux |
| anxious | anxieux |
| courageous | courageux |
| dangerous | dangereux |
| delicious | délicieux |
| desirous | désireux |
| disastrous | désastreux |
| envious | envieux |
| fabulous | fabuleux |
| glorious | glorieux |
| gracious | gracieux |
| harmonious | harmonieux |
| hideous | hideux |
| laborious | laborieux |
| luxurious | luxueux |
| marvellous | merveilleux |
| miraculous | miraculeux |
| monstrous | monstrueux |
| mysterious | mystérieux |
| nervous | nerveux |
| numerous | nombreux |
| odious | odieux |
| outrageous | outrageux |
| perilous | périlleux |
| pious | pieux |
| pompous | pompeux |
| prestigious | prestigieux |
| precious | précieux |
| presumptuous | présomptueux |
| prodigious | prodigieux |
| religious | religieux |
| serious | sérieux |
| sumptuous | somptueux |
| superstitious | superstitieux |
| tumultuous | tumultueux |
| victorious | victorieux |
| virtuous | vertueux |
| voluptuous | voluptueux |
Usage examples
Dangerous → dangereux
- Ce chien est dangereux. – “This dog is dangerous.”
- Cette route est dangereuse. – “This road is dangerous.”
Curious → curieux
- Je suis curieux de savoir la vérité. – “I am curious to know the truth.”
- Elle est curieuse de tout. – “She is curious about everything.”
Generous → généreux
- Il est très généreux avec ses amis. – “He is very generous with his friends.”
- Elle a été généreuse avec nous. – “She was generous with us.”
Serious → sérieux
- C’est un problème sérieux. – “It is a serious problem.”
- Il est très sérieux dans son travail. – “He is very serious in his work.”
Nervous → nerveux
- Je suis nerveux avant l’examen. – “I am nervous before the exam.”
- Elle semble nerveuse aujourd’hui. – “She seems nervous today.”
Ambitious → ambitieux
- Il est très ambitieux dans sa carrière. – “He is very ambitious in his career.”
- Elle est ambitieuse et travaille beaucoup. – “She is ambitious and works a lot.”
Anxious → anxieux
- Je suis anxieux avant le voyage. – “I am anxious before the trip.”
- Il avait l’air anxieux. – “He looked anxious.”
Luxurious → luxueux
- Ils ont acheté une voiture luxueuse. – “They bought a luxurious car.”
- C’est un hôtel luxueux. – “It is a luxurious hotel.”
Numerous → nombreux
- Il existe de nombreux exemples. – “There are numerous examples.”
- De nombreuses personnes sont venues. – “Numerous people came.”
Precious → précieux
- Ce document est précieux. – “This document is precious.”
- Elle m’a donné de précieux conseils. – “She gave me precious advice.”
Religious → religieux
- C’est un homme religieux. – “He is a religious man.”
- Une cérémonie religieuse a eu lieu dimanche. – “A religious ceremony took place on Sunday.”
Monstrous → monstrueux
- C’est une erreur monstrueuse. – “It is a monstrous mistake.”
- Un bruit monstrueux a réveillé les habitants. – “A monstrous noise woke the inhabitants.”
Virtuous → vertueux
The spelling changes because the two languages developed from different forms of the same Latin root.
- C’est un homme vertueux. – “He is a virtuous man.”
- Elle mène une vie vertueuse. – “She leads a virtuous life.”
Feminine forms
French adjectives ending in -eux usually change to -euse in the feminine form.
| Masculine | Feminine |
|---|---|
| dangereux | dangereuse |
| curieux | curieuse |
| généreux | généreuse |
| nerveux | nerveuse |
| sérieux | sérieuse |
| mystérieux | mystérieuse |
| vertueux | vertueuse |
True exceptions
Some English adjectives ending in -ous do not correspond to French adjectives ending in -eux.
| English | French |
|---|---|
| famous | célèbre |
| obvious | évident |
| previous | précédent |
| prosperous | prospère |
| ridiculous | ridicule |
| various | divers |
These words need to be learned separately because the -ous → -eux pattern does not apply.
Summary
The ending -ous in English often corresponds to -eux in French.
The most useful examples include:
- dangerous → dangereux
- curious → curieux
- generous → généreux
- nervous → nerveux
- serious → sérieux
- mysterious → mystérieux
- virtuous → vertueux
- monstrous → monstrueux
This pattern gives English speakers a useful way to recognise many French adjectives, but it must be used with care because some English -ous words have different French equivalents.
