According to thefreedictionary, Numerical Prefixes seem to have come from Latin or Greek, but in Portuguese if you read "exa" it should sound like an esha (e.g. "oxalá" is pronounced as oshalah). Notice that the x in Portuguese seems to only have the gz sound in these cases (when there is an "exa" prefix, not when it belongs to the word itself, as in "exame").

However, Portuguese people pronounce "exa" as English people pronounce "exa", which has the exact same sound.

Therefore, why the prefix wasn't changed to the letters that most closely resemble it's real sound in Portuguese: ècsa or egza?


  • exabyte could be written in Portuguese as écsabaite or égzabaite
  • hexagon could be written as egzágono
  • exame could be written as ezame (notice that there is no "exa" prefix)
  • exa could be egza
  • "However, Portuguese people pronounce "exa" as English people pronounce "hexa"" Do you mean Portuguese people pronounce the H, even though it's not written?
    – Earthliŋ
    Jul 17, 2015 at 11:48
  • @Earthliŋ I was focusing more in the gz sound (why was the x used instead), but that's a good point as well. It seems the h may be perceptible when people pronounce the he.
    – Armfoot
    Jul 17, 2015 at 11:51
  • Are you trying to say that usually the X in Portuguese is either [(g)z] or [ʃ] but usually never [ks] (unvoiced version of [gz])? Maybe you can put all sounds into square brackets (see IPA for Portuguese), because it's not really clear to me what you're asking.
    – Earthliŋ
    Jul 17, 2015 at 11:58
  • 1
    @Earthliŋ I edited my question to clarify it better :)
    – Armfoot
    Jul 17, 2015 at 12:05
  • 1
    Your question holds false assumptions, as already mentioned. We do not always pronounce hexágono like "hegzágono".
    – E_net4
    Jul 17, 2015 at 12:36

3 Answers 3



Your assumption about the expected regular sound of x is wrong.

We have many different sounds for x in Portuguese:

  • z (/z/) - "exame", same as zebra in English;
  • cs (/ks/) - "táxi", same as taxi in English;
  • ch (/ʃ/) - "deixa", same as geisha in English;
  • ss (/s/) - "máximo", same as massing in English;

Invalid alternative spellings

You could not write écsabaite, egzágono or egza because "ec", "csa", "eg", or "gza" are not valid syllables in Portuguese.
Those words cannot be split into valid syllables.

  • 2
    exame is not pronounced the same as the English word exam in PT-PT.
    – E_net4
    Jul 17, 2015 at 13:26
  • Thanks for the feedback :) I was focusing in the usage of a common prefix ("exa") to many different languages, English included (I edited my question to reflect that). Exame, táxi, deixa and máximo are nice examples on how many ways x can be pronounced. Which is puzzling and hard for foreigners to learn. But since it seems there are new words being created as the language as changed, like in the words collapsed for not having an - (infraestrutura, autoinstrução, Autoaprendizagem, etc.). Why not ecs (e.g. emacs)?
    – Armfoot
    Jul 17, 2015 at 14:02
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    @E_net4 of course not! Corrected, thanks.
    – ANeves
    Jul 17, 2015 at 14:22
  • 3
    This is the right answer: that there are many ways of pronouncing it depending on the word. Many examples in the article Como se pronuncia o X. I especially liked that they indicate that ex- plus a consonant is /eis/, since as you rightly point out, /eks/ and /egs/ are not valid Portuguese syllables. Sexta-feira is a good, everyday example.
    – tchrist
    Jul 17, 2015 at 14:23
  • @tchrist yes "sexta-feira" sounds like "seista-feira"
    – Jorge B.
    Jul 17, 2015 at 14:26

It seems to me your assumption that

in Portuguese if you read "exa" it should sound like an esha (e.g. "oxalá" is pronounced as oshalah).

isn't correct. I can think of a few words containing exa that are pronounced the same way as hexágono, like exato (and its variants like exatamente, exatidão), examinar, exalar (the free dictionary has no entry for that word, only for exalar cheiro).

Perhaps a more adequate question would be "How do I know how to pronounce exa- prefix?".

  • 1
    Exactly! I'm going to change my question to that, if you don't mind :)
    – Armfoot
    Jul 17, 2015 at 13:43
  • Gmauch, tenho uma dúvida sobre a pronúncia do x no Brasil. Em explicar é ch como em lixo ou s de sapo? E em ex-marido é j de jarro ou z de zona? No Rio creio que é ch e j, certo?
    – Jacinto
    Sep 16, 2015 at 19:40
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    @Jacinto, eu vivo no Sul do Brasil, então minha opinião reflete o modo local de falar. Em ambos termos explicar e ex-marido o x soa como s. Ao iniciar falando ex eu não tenho como, apenas de ouvido, determinar se comecei a falar explicar ou ex-marido. Ao ouvir um carioca falando, fico com a impressão de que o que eu pronunciaria como s é pronunciado como ch e por vezes noto a adição de um i antes do s. Assim sendo, um carioca contaria os números assim: um, doix, treix e diria, creio eu, eichplicar e eich-marido.
    – gmauch
    Sep 16, 2015 at 20:15
  • Era o que eu queria saber, obrigado. Eu sabia que os cariocas chiam o s como os portugueses, enquanto na maior parte do resto do Brasil o s é mesmo s. Não tinha a certeza se era a mesma coisa com o x de explicar, texto, etc.
    – Jacinto
    Sep 16, 2015 at 20:22
  • Mas eu iria apostar que tu dizes ezmarido, mezmo, etc. Podes ver a razão nesta resposta
    – Jacinto
    Sep 16, 2015 at 20:26

The letter x is very versatile indeed, and takes quite a few sounds in Portuguese. Here are a few rules as to how it sounds, which will cover quite a few, maybe most, words.

Letters ex followed by consonant: in Portugal and Rio the x sounds ʃ as in ashamed if followed by unvoiced consonant (as in explicar) and Ʒ as in pleasure if followed by a voiced consonant (as in ex-marido). Elsewhere in Brazi the x generally sounds s insteas of ʃ and z instead of Ʒ. These are actually the rules that also apply to the pronunciation of the letter s when followed by consonant. You can see a question and answers on this topic here and learn a simple test to identify voiced and unvoiced consonants here. Bu If you don’t know about voiced and unvoiced consonants don´t worry: your vocal system will automatically take care of that for you.

Words starting with maxi like maxilar, maximal: ks as maximum, with at least on exception: in máximo the sound is s as in classmate.

Words with the suffix ixo or ixa and derivations, like prolixo, prolixamente: ks again.

Words starting with ex followed by vowel like exame, existir, exoesqueleto: z as in *maze. This includes words with the prefix exo that you mention (comes from Greek, meaning out, outside).

Words starting with hexa (meaning six). Now for the surprise. Priberam gives both z and gz as possible pronunciations! Dicionário da Academia das Ciências de Lisboa gives gz as the only pronunciation. But — I’m with the other native speakers here. I don’t recall having heard any such word pronounced with a gz, and I certainly don’t do it myself.

The words above mostly came late into the Portuguese language from Latin and Greek. Most other words with x in it (unless I’m forgetting an important class) are older and more everyday words, and the x sounds ʃ. Most words. There are lots of exptions.

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