The rules of where to put the emphasis in Spanish words are quite simple, as summarized in the following table.
| Stressed syllable | When | Example |
| last | words ending in a consonant | encontrar, usted |
| last but one | words ending in a vowel | dibujo, planeta |
| words ending in -s or -n | origen, entonces | |
| indicated by an accent mark | in every other case | séptimo, corazón, jamás, preguntó |
Accent mark
Apart from indicating an irregular place of stress, there are other uses of accent marks.
They differentiate between words with the same spelling but different part of speech (word class):
example: como - cómo; si - sí; el - él
When "u" or "i" is paired with another vowel, they form a diphthong. Accent mark is used to indicate an exception to this - when "u" or "i" should be considered as a separate vowel and syllable.
example: policía; oído; actúo; grúa
The disappearing accent mark
The use of accent mark in a word is not necessarily static. An affix can change the relative location of stress and an irregular emphasis may turn regular (or the other way round).
| león | in plural: | leones |
| interés | in plural: | intereses |
| huracán | in plural: | huracanes |
