Syllable: It’s a unit of pronunciation with a vowel sound.

Accent (prosodic): It’s the highest stress made on a syllable.

Diacritical mark: It’s the visible mark made on a vowel. It’s commonly known as written accent (Only one diacritical mark per word is correct in Spanish).

Note: In Spanish, all words have prosodic accent but not all words have diacritical mark or written accent.

 Some words have two prosodic accents, such as the words ended in “mente.” Because of these two accents, the words ended in “mente” are neither “agudas”, “graves”, “esdrújulas” nor “sobreesdrújulas.” They are special words.

Examples: activamente, cobardemente, efectivamente, religiosamente, repentinamente.

These rules are applicable only to the words with a single prosodic accent.

Proproparoxytone words (sobreesdrújulas): They are the words with the stress on the fourth(or further)-to-last syllable. They always have a written accent, except when formed from an adjective that has no written accent.

               Examples: cómpraselo, cómetelo, entrégueselo, devuélvemela, corrígeselas, véndeselo.

Important note:

In order to correctly pronounce any word that has no written accent, consider the following rules:

1. If the last letter of the word is either “n”, “s” or a “vowel”, the stress must be on the penultimate syllable.

               Examples: cosa, casa, ejemplo, gallina, volumen, entonces, certamen, injustamente, abiertamente

2. In the other cases, the stress must be on the last syllable.

               Examples: analizar, pared, arroz, virtud,