Hopefully, you will find that your favorite Spanish guide or dictionary has a section on pronunciation. If that section is somehow typical, it will largely deal with the pronunciation of individual sounds in the language. It is certainly a useful starting point to consider how to pronounce, for example, “la r in Spanish” or “vowel ‘i’ in Spanish” in isolation, or in certain example words. But your strategy for improving your pronunciation should also go beyond this letter-by-letter or sound-by-sound approach.
If you want your speech to sound as natural and intelligible as possible, the timing of your speech may be as important as, for example, the quality of individual vowels. To illustrate the importance of rhythm in speech, think in English about how to differentiate a ‘lighthouse keeper’ from a ‘housekeeper’. In this article, I will outline two important elements of rhythm and how they work in Spanish: syllabification and accent. Syllabification is the process of organizing the sounds in a word or expression into syllables and it can differ somewhat from language to language. Informally, when we clap a word or phrase, we clap once for each syllable.
By “stress” we mean making certain syllables prominent in relation to others around them. For example, in English, the first syllable is stressed in the words ‘Inca’ and ‘impotent’, while the second syllable is stressed in ‘incur’ and ‘important’.
One key to giving your Spanish a more natural rhythm is understanding a process called diphthongation: that is, make two vowels share a single syllable. Whenever you see a vowel ‘i’ or ‘u’ next to another vowel in Spanish, you should think about diphthongation:
(1) if the ‘i’ or the ‘u’ is the accented vowel, usually written with an accent, as in ‘María’, ‘country’ (“country”), ‘duo’ (“duet”) or ‘owl’ (“owl”) – then the two vowels will form separate syllables: Ma.rí.a, pa.ís, du.o, bu. (h) or (remember, the Spanish letter ‘h’ is not pronounced);
(2) otherwise the ‘i’ or ‘u’ will generally be pronounced on the same syllable as the vowel next to it: so Spanish speakers would pronounce ‘San Die.go’ as three syllables, not four as in English ‘San Diego ‘; The Spanish ‘u.sual’ has two syllables, compared to the English ‘u.su.al’. In these cases, the ‘i’ or ‘u’ “slides” into the other vowel, a bit like an ‘y’ or ‘w’ in English. In other cases, it could “slip” from the other vowel, as in ‘au.la’ (“classroom”, “conference room”), ‘six’ (“six”).
Especially in some parts of Spain, there is some variation in (2): there is a greater tendency to separate syllables at the beginning of words (for example, ‘bi.ó.lo.go’, although ‘bió.lo.go’ also possible), and where a word with clearly separated syllables has an influence on another by analogy. Thus, the word ‘ví.a’ (“way”, “route”, “way”), always pronounced as two syllables, tends to influence the pronunciation of the speakers of “vi.a.ble” (“viable” ); ‘rí.e’ (“he / she laughs”) tends to influence ‘ri.en.do’ (“laughing”), while on the other hand speakers generally pronounce ‘sien.do’ (“to be”) like two syllables.
The verb forms and triphthongs ‘you’
Note that the verb endings ‘you’ always contain a diphthong. In some cases, a vowel ‘i’ or ‘u’ can occur both before and after another vowel, resulting in a triphthong: three vowels that share a syllable. Examples include the ‘you’ form of regular -iar verbs (so ‘(you) change’ will be pronounced in just two syllables: ‘cam.biáis’) and some other words like ‘buey’ (“ox”; “idiot”) and ‘Pa.ra.guay’.
Syllabification in normal speech
The patterns we have presented above apply to what we might call “careful” speech: for example, the style used by a newsreader reading the autocue. In normal, relaxed speech, diphthongation goes a couple of stages further:
(1) none two vowels together tend to share a syllable;
(2) even through the limits of words, two vowels can share a syllable.
So in careful speech, ‘English poet’ (“English poet”) would be syllabled as’ po.e.ta.ing.lés’, in five syllables, but in normal relaxed speech it would tend to be ‘poe.taing .les’; ‘eat and drink’ (“eat and drink”) would be ‘co.mei.to.ma’; ‘my friend’ would be ‘mia.mi.go’, etc. The word ‘carrot’ (“carrot”) is often pronounced with three syllables, ‘za.na (h) o.ria’: As mentioned above, the ‘h’ is not pronounced and does not affect syllabification.
In general, every word in Spanish has exactly one stressed syllable (with a couple of exceptions that we’ll consider in a moment). The “default” is for the penultimate syllable to be stressed, and this is considered to be the case for about 80% of words.; words ending in a consonant, except plurals -s, are regularly stressed in the final syllable. Where the stressed syllable of a word is not predicted by these rules – and even in some cases where it is – the stressed syllable is marked with a written accent, as in ‘easy’ (“easy”), ‘metrico’ (“metric “). But even when the regular rules are applied, subtly, we must apply the above diphthongation rules when counting syllables. Thus, in ‘monopolio’ (“monopoly”), it is the penultimate ‘o’ that is stressed: mo.no.pó.lio, since the final -lio forms a single syllable. In the word ‘continuous’, the ‘i’ is stressed, since the word is syllabized ‘con.ti.nuo’, in three syllables, not four (unlike the English ‘con.ti.nu.ous’) .
A couple of exceptions to the one accent per word rule are worth mentioning. First, some “function words” generally do not have any stressed syllable. These include:
– possessive (‘my’, ‘you’, etc.);
– clitic pronouns (the pronouns that come before the verb: ‘me’, ‘te’, ‘se’, etc.);
– single syllable prepositions (‘de’, ‘por’, ‘a’, etc.);
– various conjunctions when not used in a direct question (‘when’, ‘while’, ‘who’, etc.).
Where these stress-free words end in a vowel, they are mature candidates to form a diphthong with the next word in rapid speech, as in ‘my friend’ (“my friend”: mia.mi.go), ‘I hurry ‘(“I hurry”: mea.pu.ro)’ otherwise ‘(“another way”: deo.tra.ma.ne.ra).
Finally, Spanish adverbs ending in -mente are the greediest words and usually have two stressed syllables. In effect, the suffix -mente is treated as a word in its own right in terms of accent (and is actually derived from the word “mind”); then the adverb carries another accent instead of the corresponding adjective. For example, ‘easy’ (“easy”) is stressed on the first syllable; ‘easily’ (“easily”) is stressed on both the first and the penultimate syllable. The word ‘frequent’ (“frequent”, “common”) is regularly stressed on the penultimate syllable (the ‘cuen’, which contains diphthong, of course!); the adverb ‘frequently’ (“frequently”, “commonly”, “often”) in both cuen ‘and’ men ‘.
In this article, we present some tips to improve the rhythm of your Spanish pronunciation. If you can get into the habit of following the patterns we present to you, this will help your Spanish sound more natural and intelligible to native speakers.
 Obviously, this is an informal, intuition-based definition of “syllable.” The Spanish pronunciation section of the Spanish English website gives a more formal definition.
 For more details and examples, see: Chitaron, I. & Hualde, JI (2007), “From hiatus to diphthong: the evolution of vowel sequences in romance” in Phonology (24): 37-35.
 Source: Alcoba, S. & Murillo, J. (1998), “Intonation in Spanish” in “Systems of intonation: a survey of twenty languages”, CUP.