French prefixes are word parts added to the beginning of a root word to change its meaning. This page covers common prefixes, how they modify meaning, usage rules, and examples.
French prefixes are short elements placed at the beginning of a word to alter its meaning. They can indicate negation, repetition, location, intensity, or other nuances. Understanding prefixes helps expand vocabulary and decode unfamiliar words.
- Common prefixes come from Latin or Greek origins.
- They do not change the root word’s grammatical role (e.g., noun, verb, adjective).
- Some require adjusting the spelling or dropping duplicate letters.
Common French Prefixes
Below are some of the most frequent French prefixes, their meanings, and example words.
| Prefix | Meaning | Example Word | Example Meaning |
|---|---|---|---|
| re- | again, back | refaire | do again |
| dé- | undo, reverse, remove | défaire | undo |
| in- / im- / il- / ir- | not, opposite | impossible, illégal, irrégulier | impossible, illegal, irregular |
| pré- | before | prévoir | foresee |
| uni- | one, single | uniforme | uniform |
| trans- | across, beyond | transporter | transport |
| auto- | self | automatique | automatic |
| inter- | between, among | international | international |
| sur- | over, above, too much | surcharge | overload |
| sous- | under, below | sous-marin | submarine |
El prefijo francés que se usa para significar 'no' o 'opuesto' es ___.
Which prefix would you use in French to mean 'not' or 'opposite'?
in-
The prefix "in-" (along with its variants im-, il-, ir-) is used in French to indicate negation or opposition, as in "impossible" or "illégal." Other prefixes like "re-" mean again, "pré-" means before, and "auto-" means self.
How Prefixes Change Meaning
French prefixes modify the root word’s meaning without changing its part of speech. They can:
- Indicate repetition or return (re-)
- Signal negation or opposition (in-, im-, il-, ir-, dé-)
- Specify time or order (pré-)
- Describe position or direction (trans-, sur-, sous-)
- Show intensity or excess (sur-)
- Refer to the self (auto-)
See examples below:
| Root Word | With Prefix | Meaning |
|---|---|---|
| faire (to do) | refaire | do again |
| possible | impossible | not possible |
| légal | illégal | illegal |
| marin (marine) | sous-marin | submarine (underwater) |
| voir (see) | prévoir | foresee |
| charger (load) | surcharge | overload |
Usage Notes
Here are some important tips for using French prefixes correctly:
- Negation Prefixes Vary
Use in-, im-, il-, or ir- depending on the first letter of the root word:
- in- before most consonants/vowels (inexact)
- im- before b, p, m (impossible)
- il- before l (illégal)
- ir- before r (irrégulier)
- Avoid Double Letters
If the root word begins with the same letter as the prefix’s ending, drop one letter:
- re + écrire = réécrire (double é)
- sub + superscript = *not a common example, but principle applies
- Hyphens Are Uncommon
Most prefixes attach directly without a hyphen, except in some cases for clarity or style (auto-immune).
- Latin vs Greek Origins
Most common prefixes are Latin; a few (auto-, photo-) are Greek.
When do you use im- instead of in- for negation in French?
Before b, p, or m
The prefix im- is used before the consonants b, p, and m for easier pronunciation (e.g., impossible). In- is used before other consonants and vowels.
Examples
Here are some full French sentences using prefixes. Each prefix appears at least once.
| French Sentence | English Translation | Prefix |
|---|---|---|
| Je dois refaire mes devoirs. | I have to redo my homework. | re- |
| Ce problème est impossible à résoudre. | This problem is impossible to solve. | im- |
| Elle est allée sous l’eau avec un tuba. | She went underwater with a snorkel. | sous- |
| Il a prévu une réunion demain. | He scheduled a meeting for tomorrow. | pré- |
| La surcharge électrique est dangereuse. | Electrical overload is dangerous. | sur- |
| Ce document est illégal. | This document is illegal. | il- |
| L’avion a traversé l’Atlantique. | The plane crossed the Atlantic. | trans- |
| Cette situation est irrégulière. | This situation is irregular. | ir- |
| La voiture est automatique. | The car is automatic. | auto- |
| Le pavé a été délogé. | The paving stone was dislodged. | dé- |
Il a prévu une réunion demain.
He scheduled a meeting for tomorrow.
The prefix 'pré-' means 'before,' and "prévu" means 'planned' or 'scheduled.'
Summary
French prefixes are key building blocks for expanding vocabulary. Key points:
- Prefixes add meaning without changing grammar.
- Common functions: negation, repetition, position, intensity.
- Negation prefixes match root word initials (in-, im-, il-, ir-).
- Spelling may adjust to avoid duplicates.
- Practice with examples to build intuition.
Flashcards (1 of 10)
- Prefix: re-
- English Translation: I have to redo my homework.
Last updated: Thu Jun 12, 2025
