How to recognize hiatuses and diphthongs: 9 steps

Table of contents:

How to recognize hiatuses and diphthongs: 9 steps
How to recognize hiatuses and diphthongs: 9 steps

How many times have you had to explain to your children the difference between a hiatus and a diphthong and have you always had to resort to little understandable manuals? Or, maybe, do you remember the time you took an aptitude test and this question came up? Often times, it is difficult to locate a hiatus or diphthong in a word, and it is even more difficult to distinguish between them. So that it is not difficult for you to distinguish between them, and without having to suffocate between complex spelling rules, you have at your disposal the following methods.


Method 1 of 2: Know what a hiatus and diphthong are

How to recognize hiatuses and diphthongs 1
How to recognize hiatuses and diphthongs 1

Step 1. Learn what a hiatus is

A hiatus occurs in a word when two vowels are together but belong to different syllables. There may be hiatuses with one of the two accented vowels or both without accents. You will see that there are several ways in which a hiatus can form, namely:

  • You can find two open vowels (a, e, o) together, but belonging to different syllables. The combinations can be varied and in any order: aa, ee, oo, ae, ea, ao, oa, eo, oe.

    Some examples are: Saavedra, preeminent, coordinate, bring, fight, kaolin, alibi, cameo, rude.

    Once syllabically separated, they are: Sa-a-ve-dra, pre-e-mi-nen-te, co-or-di-no, tra-er, pe-le-a, ca-o-lín, co- ar-ta-da, ca-ma-fe-o, so-ez.

  • Likewise, there is the combination of an open vowel (a, e, o) with a closed one (i, u), also of different syllables and in any order. In this case, the closed vowel always has an accent: aí, ía, aú, úa, eí, íe, eú, úe, oí, ío, oú, úo.

    You can see it in the following examples: collapsed, followed, howl, spike, possessed, stubborn, gather, evaluate, gnaw, mess, noumenon, score.

    This is its decomposition: con-tra-í-do, se-guí-a, a-ú-lla, pú-a, po-se-í-da, por-fí-e, re-ú-na, e -va-lú-e, ro-í-do, li-o, no-ú-me-no, pun-tú-o.

  • The same previous combinations, but with “h” inserted, do not alter the hiatus condition.

    In these examples you can confirm it: deepen (a-hon-dar), owl (ow-ho), forbid (prohibit-h-ba).

How to recognize hiatuses and diphthongs 2
How to recognize hiatuses and diphthongs 2

Step 2. Learn what a diphthong is

A diphthong occurs when two vowels are found in the same syllable. Therefore, unlike in the case of the hiatus, you must pronounce them together. There are also different combinations:

  • You can distinguish it composed of an open vowel (a, e, o) and a closed vowel (i, u) in any order. Thus, the diphthongs ai, ia, ei, ie, oi, io, au, ua, eu, ue, ou, uo are produced.

    You can check it in the following examples: you speak, raises, thirty, belly, I hear, violin, pattern, hold, leukocyte, source, Lourdes, monster.

    These are separated by syllables like this: ha-bláis, arre-cia, trein-ta, vien-tre, oi-go, vio-lín, pau-ta, a-guan-ta, leu-co-ci-to, fuen -Te, Lour-des, mons-truo.

  • You can also find it formed by two closed vowels (i, u), that is, ui, iu, as in elusive or diuretic, that is, hui-di-za, diu-ré-ti-co.
How to recognize hiatuses and diphthongs 3
How to recognize hiatuses and diphthongs 3

Step 3. See what happens when there are three vowels together

Sometimes you will not only find two vowels linked, but three. In this case, hiatuses and triphthongs can also occur, which is how they are called.

  • If you locate three vowels together in the closed-open-closed order, as in the case i-a-i, which are pronounced in two syllables (i-ai), it is a hiatus. The separation between syllables is always between the first closed vowel and the open one, So a word like "veríais" is separated into ve-rí-ais, with an accent in the closed one.

  • On the other hand, if you pronounce the three vowels in a single syllable, you have a tripthong in front of you, and it is always composed of the following sequence of vowels: closed-open-closed. Not all the combinations are given in Spanish, but the most common ones are: iai, iei, uai, uei, ioi, as you can see in trust, lose, find out, cushion, dioecious, decompose: trust, ex-tra -ve, a-ve-ri-guáis, a-mor-ti-güéis, dioi-ca.

Method 2 of 2: Easily distinguish a hiatus and a diphthong by steps or by pronunciation

How to recognize hiatuses and diphthongs 9
How to recognize hiatuses and diphthongs 9

Step 1. Find the vowels that are together

To differentiate between a hiatus and a diphthong, you first have to find two vowels together in a word, with any possible combination.

You can find two open vowels (a, e, o), two closed vowels (i, u), one closed and one open, or one open and one closed. They may or may not have an accent. If an "h" appears in between, ignore it


Step 2. See if they are two open vowels

In the case that they are two open vowels together (with or without accent), it will always be a hiatus, and they will be pronounced separately, in two syllables.

Examples: spinning top, pawn, reissue, mold


Step 3. See if they are an open vowel and a closed vowel, or vice versa

In these cases you must follow one of the following two options:

  • If one of the two vowels has a tilde, the combination in which the tilde is in the closed vowel (i, u) will always be hiatus, and diphthong if it is on the open vowel (a, e, o). Examples of hiatus: brotherhood, conceited, cold, forbid, howl. Examples of diphthong: free, correct, understand.
  • If none of the vowels has an accent, it is a diphthong. Examples: stay, decency, sequence, gradual, self-conscious, howl.

Step 4. Determine if there are two closed vowels, with or without accent marks

Any combination (iu, ui) is a diphthong.

Examples: flow, ruin, restored, friends


Step 5. Inspect the word out loud

Remember that both the hiatus and the diphthong are formed by two vowels together. The difference is in how they are pronounced, together or separately, that is, if they belong to the same syllable or not.

You should find two or more vowels that are together in the word you are analyzing


Step 6. Decompose the word to pronounce the syllables

Once you've found them, try breaking it down into syllables. It is advisable to read it aloud, breaking it into syllables, since sometimes it can be a bit difficult to do it in writing. Examples: com-pa-ñí-a, ex-tra-viar.

  • Listen to your voice If you pronounce the vowels together, you are in front of a diphthong. If they sound in different syllables, it is a hiatus.
  • If you are not clear on the pronunciation, you should use the previous steps to easily distinguish a hiatus and a diphthong.


  • To make things easier for you, you can access the Silabeador website that the University of Las Palmas de Gran Canarias has created to break down words by syllables and give you information on the presence of hiatuses and diphthongs. Use it, it is very easy and useful.
  • Two open vowels never form a diphthong. If they are read together, it is a phenomenon known as sinalefa, which is a resource used mostly in lyrics.
  • The tilde in closed vowels (i, u) destroys the diphthong.


  • As indicated by the Royal Spanish Academy, accessing its resources and introducing the term "hiatus" or "diphthong", the pronunciation of these that occurs in different Spanish-speaking countries and regions, differs in many cases, thus If you are not very good at hyphenation, you can get confused. Hence, it is recommended that you follow what is described in the steps to easily distinguish a hiatus and a diphthong.
  • This instruction manual is not a compendium of spelling or grammar of the Spanish language. It only aims to provide you with different methods so that you are able, easily, to locate, identify and distinguish hiatuses and diphthongs of words that until now resisted you.

Popular by topic