I would like to know the list of diphthongs and hiatuses in Brazilian Portuguese. Because I need the correct syllable division.

  • Niconii, with all due respect, to know that doesn't help you divide syllables. It would be better to learn about the orthography, mainly about diacritics, since there's rarely more than one possible syllabic division if you use the orthography. By the why, I am presuming you're not talking about poetic syllables.
    – Schilive
    Dec 13, 2020 at 2:51
  • What I mean is the list of diphthongs (like ai, ae, oi, ãe, ão, õe) and hiatuses.
    – Niconii
    Dec 13, 2020 at 3:18
  • Niconii, I know, that was just a comment. There's a list of diphthongs in en.wikipedia.org/wiki/Portuguese_phonology#Oral_diphthongs, but I don't know where to find a list of hiatuses in Portuguese, but I am pretty sure someone else in this site will know.
    – Schilive
    Dec 13, 2020 at 3:34
  • Niconii, I'm with @Schilive, bacause the same sequence of letters may or may not be a diphthong. For instance (a dot indicates syllable separation), coi.sa (diphthong oi), but mo.i.nho; cui.do (diphthong ui), but ru.í.do (here, as in most cases, graphical accents help); but even in moinho and ruído there's no hiatus, because we fill it with a semiconsonant (we tend to "fill" hiatuses in this way); but this is about pronunciation; presumably you're just interested in writing, and by hiatus you simply mean two adjacent vowels that are not diphthongs, right?
    – Jacinto
    Dec 13, 2020 at 16:09
  • @Jacinto Yes, it is right. I would like to know the kind of hiatuses and diphthongs.
    – Niconii
    Dec 13, 2020 at 23:20

2 Answers 2


As spelling is concerned, diphthongs and hiatuses are the same in Brazil and Portugal; there are some differences in pronunciation. I’ll focus on spelling and the “official” syllable division, which determines where you can hyphenate a word, but include some notes on pronunciation and examples with audio links where you can hear native speakers pronouncing the words; I indicate syllable division with a dot.


Falling oral diphthongs ― vowel + i or vowel + u:

ai      pai   rai.va
ei      i.dei.a   a.néis           /ɛj/ open e
         lei   jei.to                   /ej/ closed e; for many speakers in Portugal, /ɐj/ closed a
oi      cons.trói   joi.a          /ɔi/ open o
         boi   doida                /oj/ closed o
ui      cui.dar   Rui            

au      ca.cau   au.tor
eu      céu   cha.péus         /ɛw/ open e
          meu   Eu.ro.pa         /ew/ closed e
iu       riu   tra.iu      
ou      sou   Mou.ri.nho       most Portuguese and some Brazilian reduce this to /o/ closed o

Falling nasal diphthongs

ão      pão   a.vi.ão
ãe      mãe   pães
õe      põe   Ca.mões
ui       mui.to           /ũj/, it is nasal even though there is no graphical indication

Phonetic diphthongs you wouldn't guess from spelling. There are nasal phonetic diphthongs in end-of-word -em as in vem or tam.bém, pronounced [ẽj]; [ɐ̃j], rhymes with mãe, in central and southern Portugal. End-of-word -êm, as in têm, is [ẽj] in Brazil, and the double diphthong [ɐ̃jɐ̃j] in much of Portugal. End-of-word -am is as ão, [ɐ̃w], as in fo.ram. In Brasil too end-of-syllable l is usually vocalized into [w], creating phonetic diphthongs. Hence the al in Na.tal is pronounced /aw/; the ol is sol as /ɔw/ ― this diphthong /ɔw/, with an open o, does not exist otherwise in Portuguese language (ou is always /ow/, closed o, or reduced to the monophthong /o/).

Rising diphthongs starting with u occur after g and q in words like á.gua, qua.tro, a.guen.tar, tran.qui.lo, ar.guir*, q.rum. This is not universal though: the u in these ui and ue is silent in many such words, like es.qui.lo, ma.la.gue.ta, etc. If you do not know, the only way is to look up a dictionary that shows pronunciation, like Michaelis (Brazilian standard), Priberam (you can select Brazilian or European standard) or Infopédia (European standard).


There are true hiatuses in Portuguese such as in a.é.ria and in fri.í.ssimo, that is two adjacent vowels that belong to different syllables (dot shows syllable separation), and are therefore pronounced separately, not as a diphthong. But then there lots of “official” hiatuses that are undone in standard pronunciation. This can vary a great deal between Brazil and Portugal, and within Brazil itself. For instance, leão has officially two syllables and a hiatus, le.ão, but the Portuguese and many Brazilians turn the e into the semivowel [j] and pronounce the word as the triphthong /ljɐ̃w /; in Portugal this is the standard pronunciation, as shown in dictionaries such as Infopédia. The same goes for pra.te.a.do, where e.a is “officially” a hiatus, but is pronounced as the rising diphthong /ja/; in Forvo one Brazilian pronounces it as a diphthong, another as a hiatus. Now this is pronunciation. Official orthography has them as hiatuses, which means that you can hyphenate the word there at the end of a line (le- ão, prate- ado, although some such hyphenations are discouraged anyway).

So I’ll now follow the spelling and show official hiatuses regardless of whether they are pronounced as hiatuses or not. And I’m pleased to announce that off all possible twenty-five pairs of vowel letters, twenty-four can be found as hiatuses in words recorded in dictionaries, and the twenty-fifith can be found in a word not recorded in dictionaries. One pair, say i.a, can appear in several different hiatuses, because the hiatus may be formed of just the two letters (pi.ano), or each of the letters may be part of a diphthong (pi.ão, boi.a, boi.ão), the second vowel may be nasal (cri.ança), and so on. I’ll group the examples according to the two letters on either side of the hiatus, and highlight in boldface all the letters that belong with them, as in the examples above.

a.a      ba.a.miano   A.bra.ão
a.e      a.e.ro.por.to
a.i       pa.í.s   a.in.da
a.o      ca.ó.ti.co   a.on.de
a.u      sa.ú.de

e.a      se.a.ra   á.re.a   le.ão
e.e      com.pre.en.der   can.de.ei.ro
e.i       de.ís.mo   de.i.fi.car
e.o      te.o.ria   e.ó.li.co   al.vé.o.lo  le.ões
e.u      re.u.ni.ão   con.e.ú.do

i.a      í.a.mos   Vi.a.na   cri.an.ça   pi.ão   cons.ci.ên.ci.a
i.e      vi.e.la   fri.e.za   cons.ci.ên.ci.a
i.i       chei.i.nho   fi.íssi.mo
i.o      e.tí.o.pe   i.o.do
i.u      mi.ú.do

o.a      bo.a.to   vo.an.do   Jo.ão
o.e      co.e.lho   mo.e.la   do.en.ça   al.go.do.ei.ro
o.i       mo.i.nho
o.o      en.jo.o   zo.ó.lo.go   co.o.pe.ra.ção
o.u      co.u.ti.li.za.ção      not in any dictionary; has been used here

u.a      tá.bu.a   lu.a   su.a.ve   Lu.an.da   su.ão
u.e      du.e.lo   du.en.de   cu.ei.ro
u.i       su.í.no   ru.i.do.so
u.o      du.o.dé.ci.mo   ár.du.o   re.cu.o
u.u      du.un.vi.ra.to   (no audio, phonetic transcription only)

How can you tell whether two vowel letters make a diphthong or a hiatus?

You can in most cases when the main stress is there. Compare pais and país: the accented í tells you that it is a hiatus, pa.ís, and that the i is the stressed vowel, whereas in pais, ai is a diphthong. The same with sda, rdo, etc.: the two adjacent vowels make a hiatus, and accent shows the stressed vowel; similar sequences with no accent, like cauda, cuido, have diphthongs.

Exception. No accent is used if the second vowel is followed by l, m, n, r, or z, and makes a syllable with it; that vowel is still stressed and it is a hiatus though: pa.ul, Co.im.bra, a.in.da, ru.ir, ju.iz. Note that these consonants must belong to the same syllable with the preceding vowel: Ra.ul (hiatus), but Pau.lo (diphthong), because in Paulo the l forms a syllable with the following o, not the preceding u. No accent is used either if the second vowel is followed by nh: ra.i.nha.

Another exception. So far we’ve relied on stressed diphthongs not requiring accents. But they do in the third-to-last syllable: te.ra.pêu.ti.co. How can we tell it is not te.ra.pê.u.ti.co. Well, I don’t know this is a general rule, but the only hiatuses that I know of that are accented in the first vowel are é.o (al.vé.o.lo), í.a (trí.a.da, Lu.sí.adas) and í.o (va.rí.o.la, pe.rí.o.do, mí.o.pe), and there is no diphthong eo, ia or io (remember, oral diphthongs are vowel + i/u, or follow the pattern qu/gu + vowel). So it is safe to assume that anything like êu is a diphthong. We also put an accent on diphthongs éi, éu and ói at the end of a word (including monosyllables): pa.péis, cha.péu, véu, sóis, cons.trói, so that we know the accented vowel is open, not closed. Again, this does not fit the pattern é.o or í.o.

The real problem is in unstressed syllables. For instance, it is cui.da.do, but ru.i.do.so; we cannot, as before, put an accent on the i of the hiatus, because it is unstressed; the stressed syllable is do. Same with rei.fi.car and de.i.fi.car; reumático and re.uni.do. So any pair vowel + i/u in an unstressed position could in theory be a diphthong or a hiatus. If you do not know, the only way is to look up a dictionary that shows syllable separation, like Aulete , Michaelis (Brazilian standard), Priberam (you can select Brazilian or European standard) or Infopédia (European standard).

  • Good answer! The problem with hiatuses is pretty complex, as you said, since hiatuses can become diphthongs, but something that I don't know is how many words can be both, without the hiatus becoming a diphthong I mean? For example, the word “saudade” has basically two pronunciations, one with a hiatus (/sa-u/) or with a diphthong (/sau/). It is just a comment, but I think interesting the word “saudade”. Congrats.
    – Schilive
    Dec 16, 2020 at 0:34
  • @Schilive, I wouldn't know how many of those there are. In Portugal quite a lot a people, most, I reckon, pronounce io in words like tio and rio as a diphthong!
    – Jacinto
    Dec 16, 2020 at 0:40
  • it was more like a question to the air. Where I live in Brazil, “tio” and “rio” have a hiatus, but it becomes a diphthong in fast speech, not needing to be that fast.
    – Schilive
    Dec 16, 2020 at 1:00
  • @Schilive, I had some notion of those pronunciations of saudade. I actually wanted to use a word of that family, with the hiatus pronuntiation, for a contrast like sa.u.do.so versus cau.te.loso to ilustrate that an unstressed au can be hiatus or diphthong, and was quite upset to find out that nearly all dictionaries give the diphthong pronunciation only. Aulete is the exception.
    – Jacinto
    Dec 16, 2020 at 1:00
  • @Schilive, whereas I fill the hiatus with the semivowel [j], /tijw/, creating a triphthong. Once comparing my tio with Portugese coleages that do the diphtong, and a Carioca, I though that the Carioca did a hiatus, but she found her pronunciation like my triphthong. I guess /ti.u/ and /tijw/ are a lot closer to each other than either is to /tiw/.
    – Jacinto
    Dec 16, 2020 at 1:03

If you really just want the list of diphthongs, then the Wikipedia article on ditongos shows a list of the existing diphthongs: https://pt.wikipedia.org/wiki/Ditongo
They're not organized, but they're there.

But you should consider the points raised by Jacinto and Schilive in the comments to your question.

If what you are looking for is to split words into syllables occasionally, the Priberam online dictionary splits the words into their syllables.

See e.g. Priberam splitting "bolacha" into its 3 syllables:

  • bo·la·cha

"bolacha", in Dicionário Priberam da Língua Portuguesa [em linha], 2008-2020, https://dicionario.priberam.org/bolacha [consultado em 14-12-2020].

If what you want is an exhaustive list of diphthongs, a quick internet search will provide you with many results even if you search in English, such as https://www.learningportuguese.co.uk/guide/pronunciation/diphthongs

Wikipedia has plenty of information on this, both in Portuguese (more specific and with sillabary examples) and in English (more technical, with IPA notations and few examples).

Note that there are also some triphtongs (tritongos), even if they are rare: U·ru·guai, quais·quer, etc.
The Wikipedia article on triphthong mentions portuguese examples.

  • I am sorry, but what about the hiatuses? If I didn't see it, I'm sorry.
    – Schilive
    Dec 14, 2020 at 22:46
  • I don't know much about hiatuses, other than what a quick search teaches. Sorry, I'm not sure what you are looking for in that regard, or how I could help. You'll need more complete help from someone else. :)
    – ANeves
    Dec 15, 2020 at 23:47
  • 1
    Faz-me uma certa espécie estes gajos que acham que a pergunta merece uma resposta mas não um voto.
    – Jacinto
    Dec 16, 2020 at 0:16

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