French vocabulary looks large, but many words belong to the same family. Organiser, organisation, organisateur and organisé share one root; only the ending changes.
That ending is a suffix. Most French derived words are built with suffixes, and the high-frequency ones number only a few dozen. Knowing them solves three problems at once:
- Reading: when you meet a long word you have never seen, splitting off the suffix tells you its part of speech and roughly what it means
- Writing: you can express the same idea as a verb, a noun or an adjective, which keeps you from repeating yourself
- Gender: many suffixes decide on their own whether a noun takes le or la
Below, the suffixes are sorted by the direction of the change.
Verb → noun
This is the group you will use most.
| Suffix | Gender | Meaning | Examples |
|---|---|---|---|
| -tion / -sion / -ation | feminine | action, result | organiser → l'organisation, décider → la décision |
| -ment | masculine | action, process | développer → le développement, changer → le changement |
| -age | masculine | action, often concrete | laver → le lavage, nettoyer → le nettoyage |
| -ure | feminine | result, state | blesser → la blessure, ouvrir → l'ouverture |
| -ance / -ence | feminine | state | espérer → l'espérance, exiger → l'exigence |
| -eur / -euse | person | the person who does it | vendre → le vendeur / la vendeuse |
| -teur / -trice | person | the person who does it | organiser → l'organisateur / l'organisatrice |
| ending dropped | mostly masculine | the action itself | appeler → l'appel, regarder → le regard, choisir → le choix |
A few additions:
- Verbs in -duire always become -duction: produire → la production, réduire → la réduction, traduire → la traduction, introduire → l'introduction.
- Verbs in -ir and -re often derive from a conjugated stem: naître → la naissance, connaître → la connaissance, croître → la croissance.
- The "ending dropped" group has feminine nouns too: visiter → la visite, demander → la demande, aider → l'aide. Learn the gender with the word.
Verb → adjective
| Suffix | Meaning | Examples |
|---|---|---|
| -able / -ible | that can be … | faire → faisable, lire → lisible, boire → buvable |
| present participle -ant | active, causing … | intéresser → intéressant, fatiguer → fatigant |
| past participle | passive, in a state of … | fermer → fermé, fatiguer → fatigué |
| -if / -ive | tending to … | créer → créatif, agir → actif |
The spelling before -able follows the verb's pronunciation rules: manger → mangeable (the e stays after g to keep it soft), remarquer → remarquable.
Participle and adjective can be spelled differently
In a set of words, the present participle and the matching adjective sound the same but are spelled differently. In writing you usually need the adjective, so the left-hand column is the one to learn:
| Adjective | Present participle | Example |
|---|---|---|
| fatigant | fatiguant | un travail fatigant |
| convaincant | convainquant | un argument convaincant |
| provocant | provoquant | une attitude provocante |
| négligent | négligeant | un employé négligent |
| différent | différant | des points de vue différents |
| précédent | précédant | l'année précédente |
| équivalent | équivalant | un diplôme équivalent |
The pattern: the adjective drops the u or e the verb adds to keep its sound (fatigu-, convainqu-, néglige-), and -ant may become -ent. The participle follows the verb stem; the adjective does not.
Adjective → adverb
This is the most regular group. It is almost always -ment, in four cases.
① Feminine form + -ment (the most common)
lent → lente → lentement · heureux → heureuse → heureusement · actif → active → activement · doux → douce → doucement · franc → franche → franchement
② Masculine form ending in a vowel: add -ment directly
vrai → vraiment · poli → poliment · absolu → absolument · aisé → aisément
③ -ant → -amment, -ent → -emment
constant → constamment · courant → couramment · suffisant → suffisamment · évident → évidemment · récent → récemment · prudent → prudemment
Both spellings are pronounced the same, [amɑ̃], so only the spelling of the adjective tells you whether to write a or e. The exceptions are lent → lentement and présent → présentement.
④ A few add é or change shape
précis → précisément · énorme → énormément · profond → profondément · gentil → gentiment · bref → brièvement
And the most common adverbs do not use -ment at all: bon → bien, mauvais → mal, meilleur → mieux.
Adjective → noun (naming a quality)
| Suffix | Gender | Examples |
|---|---|---|
| -té / -ité | feminine | libre → la liberté, facile → la facilité, fier → la fierté |
| -eur | feminine | grand → la grandeur, blanc → la blancheur, long → la longueur |
| -esse | feminine | jeune → la jeunesse, riche → la richesse, faible → la faiblesse |
| -ise | feminine | franc → la franchise, gourmand → la gourmandise, bête → la bêtise |
| -itude | feminine | exact → l'exactitude, certain → la certitude, inquiet → l'inquiétude |
| -isme | masculine | réel → le réalisme, individuel → l'individualisme |
Nearly the whole group is feminine; only -isme is masculine. Watch out for the two kinds of -eur: when it comes from an adjective (la grandeur) it is feminine, when it comes from a verb and names a person (le vendeur) it is masculine.
Noun → adjective
| Suffix | Examples |
|---|---|
| -al / -el | la nation → national, la culture → culturel, la profession → professionnel |
| -eux / -euse | le danger → dangereux, le courage → courageux |
| -ique | l'économie → économique, l'histoire → historique |
| -if / -ive | le sport → sportif |
| -aire | la banque → bancaire, le budget → budgétaire |
| -ais / -ois / -ien | la France → français, le Québec → québécois, Paris → parisien |
The ones that look nothing alike
Some nouns seem to have no connection to their adjectives:
| Noun | Adjective |
|---|---|
| la mère | maternel |
| l'œil | oculaire |
| l'eau | aquatique |
| le doigt | digital |
| la nuit | nocturne |
| l'école | scolaire |
| le lait | lacté |
They come from the same Latin root by two routes. The left column holds popular words that evolved in everyday speech for over a thousand years and changed a lot; the right column holds learned words borrowed straight from Latin later, keeping the Latin shape.
The good news is that learned words are often close to English: maternal, ocular, aquatic, digital, nocturnal. If you speak English, lean on it — see how to carry your English vocabulary into French.
Noun / adjective → verb
| How it is formed | Examples |
|---|---|
| add -er | l'arme → armer, le rêve → rêver |
| add -iser | moderne → moderniser, général → généraliser |
| add -ifier | simple → simplifier, clair → clarifier |
| add -ir (mostly colours and body shape) | rouge → rougir, grand → grandir, maigre → maigrir, vieux → vieillir |
| put a- / en- in front | grand → agrandir, riche → enrichir, beau → embellir, long → allonger |
Prefixes: same part of speech, new meaning
| Prefix | Meaning | Examples |
|---|---|---|
| re- / ré- | again | faire → refaire, écrire → réécrire |
| dé- / dés- | reverse, remove | faire → défaire, accord → désaccord |
| in- / im- / il- / ir- | not | utile → inutile, possible → impossible, légal → illégal, régulier → irrégulier |
| mé- / més- | badly, wrongly | content → mécontent, entente → mésentente |
| pré- | in advance | voir → prévoir |
| sur- / sous- | too much / too little | estimer → surestimer / sous-estimer |
The negative prefix changes with the next letter: im- before b, p and m, il- before l, ir- before r, in- everywhere else.
Putting it to use
Reading: split the word
When you meet a long word you do not know, take it apart from both ends:
- incontournable = in- (not) + contourner (to get around) + -able (that can be) → unavoidable, essential
- désengagement = dés- (reverse) + engager (to commit) + -ment (noun) → withdrawal, pulling out
- imprévisible = im- (not) + prévoir (to foresee) + -ible → unpredictable
The suffix gives you the part of speech, the prefix gives you the direction, and you probably already know the root in the middle.
Writing: nominalisation
Swap a verb for its noun and a whole clause shrinks into a phrase:
| With a verb | Nominalised |
|---|---|
| parce que les loyers augmentent | en raison de l'augmentation des loyers |
| il faut développer les transports en commun | le développement des transports en commun est nécessaire |
| depuis que les écoles ont fermé | depuis la fermeture des écoles |
Nominalised sentences are tighter, and switching forms is a way to avoid repeating the same verb within a paragraph. Do not do it in every sentence, though: the verb form is more direct, and alternating the two reads most naturally.
Learning words: learn the gender with the suffix
When you learn a new word ending in -tion, -té or -ure, file it as feminine straight away; -ment, -age and -isme go in as masculine. That leaves only the exceptions and the words with no typical suffix to learn individually.
For how to put these words to work in an essay, see the complete TCF writing guide.