Spanish Made Simple
Rule: Stress and Accentuation
Spanish uses regularly only one written accent, the “acute” accent (such as the acute accent over á, é, í, ó, and ú). These are the rules that govern its use.
1. Words ending in a vowel (not including y) or n or s are stressed on the syllable before the last (e.g., hablado, vinieron, españoles).
2. Words ending in a consonant other than n or s (but including y) are stressed on the last syllable (e.g., entender, arrabal, codorniz, estoy).
3. Words not stressed according to the above two rules must have the written accent over the vowel of the stressed syllable (e.g., rubí, acá, nación, cortés, cáracter, fácil, páramo).
4. But note that the orthographic accent serves to distinguish words that are spelled alike but differ in meaning (e.g., tu [possessive adjective] versus tú [personal pronoun]; or, se [reflexive pronoun] versus sé [I know]; or este [demonstrative adjective] versus éste [demonstrative pronoun]; or como [declarative] versus ¿cómo? [interrogative], ¡cómo! [exclamatory]).
In most cases, the written accent represents a genuine stress on the words so marked.
5. Adjectives that have a written accent often retain the accent when adding –mente to form adverbs, even though the stress shifts to the syllable before the last (e.g., fácilmente, últimamente, cortésmente).