Goal
You’ll be able to form French adverbs correctly from adjectives, and know the genuinely specific rule for which adjective form serves as the base.
Learn
Many French adverbs are formed by adding -ment to an adjective’s feminine singular form (similar in spirit to Spanish’s -mente pattern covered from the feminine adjective base):
lente (slow, feminine) → lentement (slowly) heureuse (happy, feminine) → heureusement (happily/fortunately)
A genuinely important exception: when the masculine adjective already ends in a vowel, -ment is added directly to the masculine form instead, not the feminine: vrai (true, masculine, already ending in a vowel) → vraiment (truly), not vraiement from the feminine vraie.
Some genuinely irregular adverbs don’t follow either pattern and must be memorized directly: bon (good) becomes bien (well), not bonnement. This mirrors the same kind of good/well irregularity covered in English and Spanish, though again, the actual words are naturally different in each language.
Decision Task
You want to form the adverb from vrai (true, masculine, already ending in a vowel). Before reading on: would you add -ment to the masculine form vrai or the feminine form vraie?
Show Answer
The masculine form vrai — giving vraiment (truly). Since the masculine adjective already ends in a vowel, -ment attaches directly to it, not to the feminine form, which would produce the incorrect vraiement.
Common Mistake
Always defaulting to the feminine adjective form as the base for -ment, without checking whether the masculine form already ends in a vowel. When it does, -ment attaches directly to the masculine form instead, a genuine exception to the general feminine-base rule.
Practice Questions
1. Form the adverb from lente (slow, feminine).
Show Answer
lentement
2. Form the adverb from vrai (true, masculine, ending in a vowel).
Show Answer
vraiment
3. What is the irregular adverb form of bon (good)?
Show Answer
bien (well), not bonnement.
4. What determines whether -ment attaches to the masculine or feminine adjective form?
Show Answer
Whether the masculine form already ends in a vowel — if so, -ment attaches to the masculine form directly; otherwise, it attaches to the feminine form.
5. Form the adverb from heureuse (happy, feminine).
Show Answer
heureusement
Try It Yourself
Without looking back, form the adverb from facile (easy, already ending in -e for both genders), and explain in one sentence why this case is straightforward.
Show Answer
facilement — since facile has the same form for both masculine and feminine, there’s no ambiguity about which base to use.
Quick Check
1. What suffix forms most French adverbs from adjectives?
Show Answer
-ment
2. What adjective form is normally used as the base?
Show Answer
The feminine singular form.
3. When does -ment attach to the masculine form instead?
Show Answer
When the masculine adjective already ends in a vowel.
4. What is the irregular adverb form of bon?
Show Answer
bien
5. Form the adverb from vrai.
Show Answer
vraiment