The suffix -mente is Portuguese's answer to English -ly: it turns an adjective into an adverb of manner. Slow → slowly, lento → lentamente. It is the most productive adverb-building tool in the language, and it follows a small set of rules that, once learned, you can apply to thousands of adjectives. The catch is that two of those rules — which form of the adjective to use, and what happens to the accent — surprise almost every learner.
Rule 1: Add -mente to the feminine singular
This is the rule that trips people up first. You do not add -mente to the dictionary (masculine) form. You first put the adjective into its feminine singular form, and then attach -mente.
| Masculine adjective | Feminine form | Adverb |
|---|---|---|
| rápido | rápida | rapidamente |
| lento | lenta | lentamente |
| calmo | calma | calmamente |
| perfeito | perfeita | perfeitamente |
Ele resolveu o problema rapidamente.
He solved the problem quickly.
Ela falou calmamente com a filha.
She spoke calmly with her daughter.
Why the feminine? Historically, -mente comes from the Latin noun mens, mentis ("mind"), which was grammatically feminine. The phrase clara mente originally meant "with a clear mind," and the adjective clara agreed with the feminine noun mente. Over centuries the noun fused into a suffix, but the feminine adjective form was frozen in place. So when you write rapidamente, you are quite literally saying "with a rapid mind" — the feminine -a- is the ghost of that old agreement.
Rule 2: The written accent disappears
When -mente is attached, the original adjective loses any written accent it had. This is because the stress of the new word lands on the -men- syllable, so the adjective's own stress mark is no longer phonologically justified and is dropped in spelling.
| Adjective (with accent) | Adverb (no accent) |
|---|---|
| rápido | rapidamente |
| fácil | facilmente |
| difícil | dificilmente |
| só | somente |
| último | ultimamente |
Dificilmente eu chego antes das oito.
I hardly ever get there before eight.
Ultimamente eu ando muito cansado.
Lately I've been really tired.
So rápido keeps its accent, but rapidamente does not. This is one of the most common spelling mistakes even among native writers, so it is worth checking every time: if the base adjective had an accent, the -mente adverb does not.
Rule 3: In a series, only the last adverb keeps -mente
When you string together two or more -mente adverbs, Portuguese drops the suffix from all but the final one. The dropped ones revert to their feminine adjective form, and the single -mente at the end does the work for the whole list. This keeps the sentence from sounding clunky (three *-mente*s in a row is heavy in any language).
Ela explicou tudo clara e objetivamente.
She explained everything clearly and objectively.
Trabalhe lenta e cuidadosamente.
Work slowly and carefully.
So claramente e objetivamente becomes clara e objetivamente; lentamente e cuidadosamente becomes lenta e cuidadosamente. The first word is left in its bare feminine adjective form (clara, lenta) and only the last one is fully built. This is a register feature: it is standard in careful writing and educated speech, and it sounds polished. In very casual speech people sometimes leave both intact, but the reduced form is the recommended one.
Rule 4: Not every adjective forms a -mente adverb
The suffix is productive but not unlimited. Adjectives that describe inherent physical properties or relationships often resist it. You would not normally say azulmente (bluely) or redondamente in everyday speech, and many color, shape, and relational adjectives simply have no natural -mente adverb. When that happens, Portuguese reaches for a prepositional phrase instead — de forma + adjective or de maneira + adjective:
Ele agiu de forma estranha.
He acted in a strange way.
Resolveram tudo de maneira justa.
They settled everything in a fair way.
This de forma / de maneira escape hatch always works, so when you are unsure whether a -mente adverb sounds natural, this is the safe paraphrase.
Rule 5: bem and mal are irregular — never boamente
The two most common manner adverbs in the language are not built with -mente at all. The adjective bom (good) has the adverb bem (well); the adjective mau/má (bad) has the adverb mal (badly). These are suppletive irregulars, exactly like English good → well. There is no boamente and no mámente.
Ela canta muito bem.
She sings very well.
O projeto começou mal desde o início.
The project started badly from the very beginning.
Common Mistakes
❌ Ele resolveu o problema rápidamente.
Incorrect — the accent from 'rápido' must be dropped in the adverb.
✅ Ele resolveu o problema rapidamente.
He solved the problem quickly.
❌ Ela falou tranquilomente.
Incorrect — -mente attaches to the feminine 'tranquila', not the masculine 'tranquilo'.
✅ Ela falou tranquilamente.
She spoke calmly.
❌ Ela canta muito boamente.
Incorrect — there is no 'boamente'; the adverb of 'bom' is 'bem'.
✅ Ela canta muito bem.
She sings very well.
❌ Trabalhe lentamente e cuidadosamente.
Incorrect (heavy) — in a series only the last adverb keeps -mente.
✅ Trabalhe lenta e cuidadosamente.
Work slowly and carefully.
The tranquilomente error is the giveaway of an English speaker who has not internalized the feminine rule: they take the masculine dictionary form and bolt -mente onto it. Train yourself to first say the feminine adjective in your head (tranquila), and only then add the suffix.
Key Takeaways
- Add -mente to the feminine singular adjective: lenta → lentamente.
- The original written accent is dropped: fácil → facilmente, só → somente.
- In a series, only the last adverb keeps -mente: clara e objetivamente.
- Not every adjective forms one; fall back on de forma / de maneira + adjective.
- bem and mal are the irregular adverbs of bom and mau — never boamente.
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Start learning Portuguese→Related Topics
- Adverbs: OverviewA2 — What adverbs are in Brazilian Portuguese, why they never agree, the main semantic types, and how -mente formation and flexible placement work.
- Adverbs of MannerA2 — How Brazilian Portuguese says 'how' an action is done — the irregular bem/mal, dedicated adverbs like devagar and depressa, and the very common bare adjective used as an invariable adverb (fala baixo, corre rápido).
- Gender AgreementA1 — How Portuguese adjectives change form to match the masculine or feminine gender of the noun they describe — and which ones don't change at all.
- Adverb PlacementA2 — Where adverbs go in a Brazilian clause — flexible frequency and sentence adverbs, the fixed position of 'não' before the verb, and focus adverbs (só, até, mesmo) that scope over the element they precede.