Before describing the rules of accentuation in Spanish, a distinction must be made between "stress" and "accent".

Stress is the relative emphasis in pronunciation that may be given to certain syllables in a word, whilst the Accent is the graphic symbol that is used to mark the stress in some words according to some rules.

In Spanish, like in any other language, all words have a stressed syllable (sílaba tónica) when pronounced -other languages may have more than one stress in a word, but that is not our concern here- but not all words have the visual accent when written.

According to where the stress falls on a word, words are classified as:

• Agudas: the stress falls on the last syllable.
• Llanas or graves: the stress falls on the penultimate syllable
• Esdrújulas: the stress falls on the syllable before the penultimate syllable

Before trying to apply the rules of accentuation, a necessary condition is to know where the stress falls. Once you know where a word is stressed, you may apply the following rules of accentuation:

• Capital letters are accentuated whenever the above rules allow it.
• The grapheme "y" is considered a consonant even though sometimes is pronounced as a vowel.
• The above rules apply to latin words and expressions (e.g. referéndum) if they have an entry in the DRAE (Diccionario de la Real Academia Española), otherwise, they are written without accents and observing the latin writting.
• Words of foreign origin have accent if they are accepted by RAE, are adapted to Spanish and the rules allow it, e.g. fútbol. If accepted but not adapted, they do not have accent if the word in the source language hasn't got one, e.g. marketing
• Non-Spanish people's names do not have accent unless they have it in the original language or they have been adapted.