Adverbs in -mente & degree words

The short answer

Most advérbios em -mente (adverbs in -mente, the "-ly" words) are made from the feminine form of the adjective: rápida → rapidamente, tranquila → tranquilamente. In everyday speech Brazilians often skip -mente and use the plain adjective instead: Ela fala rápido. On top of that, a small set of intensificadores (degree words) — muito, bem, super, meio, bastante, demais, tão — say how much.

How to form it

Three details:

• Adjectives with one form for both genders just add -mente: fácil → facilmente, feliz → felizmente, simples → simplesmente.
• The written accent disappears, because the stress moves to -mente: rápido → rapidamente, último → ultimamente, prático → praticamente.
• With two adverbs in a row, only the last one takes -mente: rápida e facilmente, clara e calmamente.

Some adverbs are words of their own: bem (well), mal (badly), devagar (slowly), depressa (quickly), cedo (early), tarde (late), junto (together).

Degree words go before the adjective or adverb, except demais, which goes after it:

When to use it

• -mente in careful speech and writing, and always for sentence adverbs: Felizmente…, Sinceramente…, Geralmente…, Finalmente!
• The bare adjective in everyday speech for manner: fala rápido, custa caro, trabalha duro. Used this way it never changes: As meninas correram rápido.
• bem after a verb means "well" (cozinha bem); before an adjective or adverb, in speech, it means "really": bem caro, bem cedo.
• meio softens (meio caro), demais criticises or praises (caro demais, bom demais!), super and tão add emotion: super simpática, tão triste!

• Felizmente, ninguém se machucou.Fortunately, nobody got hurt.sentence adverb
• Ela explicou tudo clara e calmamente.She explained everything clearly and calmly.two adverbs, one -mente
• Você fala rápido demais!You talk way too fast!bare adjective + demais
• Esse restaurante é bom, mas é meio caro.This restaurant is good, but it's kind of expensive.meio = kind of
• A gente chegou bem cedo.We got there really early.bem = very (speech)

Contrasts and traps

• bem / bom, mal / mau: bem and mal describe verbs (ele canta bem); bom and mau describe nouns (um bom cantor, um cara mau).
• meio (kind of) never agrees: ela está meio cansada. Meia means "half" with a noun: meia hora. You will hear natives say meia cansada, but the norm is meio.
• demais after an adjective can be criticism or praise; the tone decides: Esse sapato é caro demais (too expensive) vs. O show foi bom demais! (really great).
• devagar is the adverb for "slowly"; lento is mainly an adjective: um ônibus lento.
• Don't put -mente on both adverbs in writing: calma e educadamente, not calmamente e educadamente.
• super is informal. Careful writing joins it to the adjective as a prefix (supercaro); in chats you will see super caro.

If you speak Spanish

The -mente rule is the same as in Spanish, including the two-adverb trick (clara y tranquilamente). The differences are small but visible: the adverb loses the accent (rápidamente → rapidamente, fácilmente → facilmente), some spellings change (exactamente → exatamente, simplemente → simplesmente, generalmente → geralmente), and muy is always muito. Medio cansada is meio cansada, and demasiado caro is usually caro demais.