Understanding the Prefixes ‘Dé-’ and ‘Des-’ in French
What Is a Prefix? (Qu’est-ce qu’un préfixe?)
A prefix is a small group of letters added at the beginning of a word to modify its meaning. In French, “dé-” (which becomes “des-” before a vowel or a silent h) is a common prefix that often indicates:
• Reversal (annulation)
• Removal (suppression)
• Intensification (renforcement)
• Separation (séparation)
For example:
• “faire” (to do) → “défaire” (to undo)
• “monter” (to climb) → “démonter” (to disassemble)
How Does “Dé-” Change a Word’s Meaning?
(Comment “Dé-” change-t-il le sens d’un mot ?)
The prefix “dé-” / “des-” alters the original word in different ways:
1. Reversal or Opposite Meaning
(Sens inverse ou opposé)
• “couvrir” (to cover) → “découvrir” (to uncover, discover)
• “brancher” (to plug in) → “débrancher” (to unplug)
2. Removal or Separation
(Suppression ou séparation)
• “boiser” (to plant trees) → “déboiser” (to deforest)
• “charger” (to load) → “décharger” (to unload)
3. Intensification
(Renforcement du sens)
• “chainer” (to chain) → “déchainer” (to unleash, intensify)
4. Transformation into “Des-” Before Vowels/Silent H
(Transformation en “Des-” devant une voyelle ou un h muet)
• “espoir” (hope) → “désespoir” (despair)
• “habiller” (to dress) → “déshabiller” (to undress)
Guessing the Meaning with Examples
(Deviner le sens à l’aide d’exemples)
Let’s analyze some words to understand how “dé-” / “des-” works:
“Déplacer” = “placer” (to place) + “dé-” → to move (change position)
“Détester” = “tester” (to test) + “dé-” → to hate (strong negative feeling)
“Désorganiser” = “organiser” (to organize) + “des-” → to disorganize
Why Is This Prefix Important?
(Pourquoi ce préfixe est-il important ?)
Understanding “dé-” / “des-” helps in:
✔ Expanding vocabulary by recognizing word patterns.
✔ Guessing meanings of unfamiliar words.
✔ Improving comprehension in reading and listening.
For more details, check out this PDF guide on prefixes.