Pronunciation: accents on diphthongs in Spanish

Learn about Spanish diphthongs

A diphthong occurs when two vowels are in the same syllable and are pronounced together.

Strong and Weak Vowels

Spanish vowels are defined as strong or weak:

For two vowels to be part of the same syllable, the vowel combination must be one of the following:

weak + weak (i, u + i, u)

weak + strong (i, u + a, e, o)

strong + weak (a, e, o + i, u)

Any other combination of vowels means that the vowels are in separate syllables, see Pronunciation: accents on hiatuses in Spanish.

How do we accentuate these words if the stress falls on the diphthong?

All words containing diphthongs follow the general rules for accentuation. If the stress is on the syllable with the diphthong, these are the rules:

1. If the combination is weak + weak, we stress the second weak vowel. For example:

2. If the combination is strong + weak or weak + strong, we always stress the strong vowel (a, e, o). For example:

See also Pronunciation: Where to stress a word in Spanish