Bom/Boa/Mau/Má (Good/Bad) vs. Bem/Mal (Well/Badly)

These two pairs of words are very similar, but they’re not interchangeable.


Good and bad are adjectives, which modify nouns (people / places / things). In Portuguese, adjectives must agree with the noun in gender and number:
bom good masc. sing. bons good masc. plur.
boa good fem. sing. boas good fem. plur.
mau bad masc. sing. maus bad masc. plur.
bad fem. sing. másbad fem. plur.


Well and badly are adverbs, which modify verbs, adjectives, and other adverbs. Adverbs are invariable, so the same words are used regardless of the gender and number of the noun.
bem well
mal badly

Which One Do I Use?

Let’s look at these examples to illustrate the difference between bom/boa (adjective) and bem (adverb).
Este telemóvel é bom. Funciona muito bem. This cell phone is good. It works very well.

Notice how bom (adjective) modifies telemóvel (noun), while bem (adverb) modifies funciona (verb).

Que boa menina, tão bem educada! What a good girl, so well mannered!

Here, boa (feminine form of bom) is modifying menina (noun), while bem is modifying educada (adjective). The adverb bem could never be paired with the noun in this sentence.

If you’re not sure which of the pairs fit in a sentence, look at the surrounding words and see whether the word describes a noun, verb, adjective, or adverb.

  • If the word will modify a noun, use a form of bom or mau, modified to match the gender and number of the noun.
  • If the word will modify a verb, adjective, or adverb, use bem or mal.

Keep in mind that if it’s easy for you to use bom/boa and bem correctly, but mau/má and mal give you a hard time, you can try mentally swapping the word for its opposite – in this case, bom or bem – to see which works. Then you can have a better idea of whether mau/má or mal would be appropriate.

Here’s one last example:

Correct: Foi um bom concerto. It was a good concert.

Incorrect: Foi um bem concerto. It was a well concert.



  • Another useful lesson, thanks, but I noticed that some of the words and phrases are missing their audio files.

    • Hi Jeremy,

      Thanks for the feedback! We normally record these audio clips in batches, so recent articles or ones with examples that have been recently modified may temporarily be without the speaker icons 🙂 Thanks for your support and keep the feedback flowin’! Abraço

      • No problem, Joel. Keeping on top of such an extensive site must be quite a job. Just thought I’d point it out so you can add it to your “to-do” list! LOL

    • Thanks for the comment! There is often a delay in us adding the audio clips when we’ve created/updated an article, since Rui records them all in a batch every week or so. But good news – These clips are now all posted! 🙂

  • Hi, I have just joined and so far I am finding the site to be excellent.

    On the pronunciation of ‘bem’, which sounds like a nasal version of the the english ‘bye’ I have just returned from Porto where it sounded like a flatter ‘bay’ but again rather nasal.

    Are there regional variations in the pronunciation of the Portuguese ‘-em’?


    • Hi, Patrick! Yes, there are regional variations for lots of sounds, ‘-em’ included. Your description of the pronunciation in Porto vs. the one demonstrated here (central Portugal/Lisbon) seems accurate 🙂

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