1 Most of thewords have one stressed syllable, but Spanish do not write accent mark on all of them.The accentuation mark depends on the number of syllables and on the word ending.

2 Palabras agudas, llanas, esdrújulas and sobresdrújulas words.

  • Agudas: the stressed syllable is the last one: comedor, camión, balcón, comer, cantar, Canadá, cristal.
  • Llanas or graves: the word is stressed on the next-to-last syllable: risa, niña, perro, ámbar, vacaciones, cantando, dinero.
  • Esdrújulas: the stress falls on the third syllable from the end: esdrújula, tácito, mágico, mímica, trágico.
  • Sobresdrújulas: the stressed syllable is previous to the third syllable from the end: dábaselo, hiciéramoslo. They usually are verbal forms with personal pronouns.

3 Rules to write the accent mark (´)

  • Accent mark is only written on multisyllabic words. Dio, vio, fue, diez, Juan, pie, fe are not marked because they are monosyllables.
  • Accent mark is written on the last vowelof the agudas multisyllabic words ending in vowel, vowel followed by n, or vowel followed by s: dominó, francés, canción, compás.
  • Accent mark is written on the next-to-last syllable of the llanas words ending in a consonant other than n or s, or ending in consonant followed by s: álbum, cárcel, mártir, césped, azúcar, árbol, bíceps.
  • Accent mark is always written on the stressed syllable of esdrújulas words: pájaros, gramática, Mediterráneo, céntimo.
  • Accent mark is always written on the sobresdrújulas words: dábasele, permítaseme.
  • The diphthongs and triphthongs are considered as one vowel for accent mark rules. In diphthongs and triphthongs the accent mark is written in the open vowel if former rules state accent mark: cantáis, cedéis, después, huésped, acuático, escuálido, despreciáis, averigüéis.
    Some diphthongs and triphthongs do not offer doubts, some others do, in fact the speakers from different areas pronounce them in different ways. That is why since 2010 the Real Academia de la Lengua considers, for accentuation mark purposes, as diphthong the combination of an open vowel (a, e, o) with a closed one (i, u), or two closed vowels. A reduced group of words in the past written with accent mark now has lost it: truhan, guion, ion, Ruan, Sion, hui (from huir), lie (from liar), crie (from criar), fie (from fiar), flui (from fluir), frio (from freír), guie (from guiar), pie (from piar), rio (from reír). The Academia also considers triphthongs for orthographic purposes, and regardless of the pronunciation in each area, the attachment of an open vowel (a, e, o) followed and preceded by one closed vowel (i, u): confiáis, despreciéis, estudiáis, fiais, miau, vieira.
    and ui always form diphthong for accentuation mark purposes; when the former rulers demand accent mark, these combinations take the written accent in the second vowel: cuídese, construí, destruí, casuística.
    The final y , although sounds like a vowel, is considered consonant for accentuation mark purposes. So the agudas words ending in –ay, -ey, -oy, -uy are written without accent mark: virrey, convoy, Paraguay.

See Diphthongs triphthongs and hiatus

  • When two consecutive vowels belong to different syllables we talk about hiatus. We write accent mark on a word according to the former rules: león (le-ón), geólogo (ge-ó-lo-go), línea (lí-ne-a).
    Regardless of how the words are pronounced in each area, the Real Academia de la Lengua considers hiatus the attachment of a close stressed vowel (i, u) followed or preceded by an open vowel (a, e, o). In addition the Academia prescribes that the stressed vowel always takes accent mark, regardless of the former rules of accentuation: comía, búho, María, caída, transeúnte, maíz, reír, oído, mía. Also the combination of two open vowels (a, e, o): área, caer, reactor or two repeated vowels: azahar, chiita, cooperativaare always hiatus. In the last two cases of hiatus also rule the rest of accentuation rules.
  • Some monosyllables and aun take accent mark to differentiate them from their homophones:

(Verb dar)
(Personal pronoun)
(Definite article)
(Adverb or adjective of quantity)
(Adversative conjunction)

(Personal pronoun)
(Possessive adjective)

(Drink or plant)
(Personal pronoun)

Personal pronoun)
(Possessive adjective)
(= Todavía)
(= Hasta, incluso)

(Verb saber or ser)
(Object or reflexive pronoun)

(Reflexive pronoun or adverb of affirmation)
(Conditional conjunction)

esto a su jefe, por favor. (, imperative, verb dar)
Ojalá el jefe buenas referencias de mí. (, present subjunctive, verb dar)
Esto cabe en una caja de cartón. (De, preposition)
No he sido yo, ha sido él. (Él, personal pronoun)
He perdido el libro en el metro. (The article el appears twice.)
Dame más agua, por favor. (Más is an adjective indicating quantity.)
Este es más bonito que el otro. (Más, adverb of quantity)
Es un hombre riquísimo, mas nadie lo diría. (The conjunction mas is equivalent to pero.)
Él lo compró para mí; esto es mío. (, personal pronoun)
Mi perro nunca ladra. (Mi, possessive adjective)
El de China es más suave que el de Ceilán. (, drink)
Te he dicho que no. (Te, personal pronoun)
Ella me ha ayudado más que tú. (, personal pronoun)
Vete a tu casa. (Tu, possessive adjective)
Aún no he acabado. (= Todavía no he acabado.)
Lleva calcetines de lana aun en verano. (= Lleva calcetines de llana incluso en verano.)
No qué significa esta palabra. (, present indicative from the verb saber)
generoso con los demás. (, imperative from the verb ser)
Se me ha olvidado. (Se, reflexive pronoun)
, por supuesto. (, adverb of affirmation)
Él solo piensa en mismo. (, reflexive pronoun)
Si tienes prisa sal cinco minutos antes. (Si, conditional conjunction)

Other homophones do not differentiate by accent mark: di (verb dar or verb decir), ve (verb ver or verb ir), fue y fui (verb ser o del verbo ir), sal (noun or verb salir), vino (verb venir or noun). Only the context sets the meaning.

  • We write accent mark on some multisyllabic terms to differentiate them from their homophones.
    The relative pronouns do not bear accent mark: que, quien, quienes, cuanto, cuanta, cuantos, cuantas. The relative adverbs do not bear accent mark: como, cuando, donde, adonde; neither the comparative forms cual and cuales. The interrogative and exclamatory pronouns bear accent mark: qué, quién, quiénes, cómo; cuánto, cuántos, cuánta, cuántas; cuál, cuáles. Also the interrogative adverbs: cuándo, dónde, por qué.

La casa que me gusta es demasiado cara. (Que is relative pronoun.)
¿Qué quiere? (Qué is interrogative pronoun.)

See Adjectival or relative subordinate clauses

  • Before 2010 the Real Academia de la Lengua set that the verbal forms taking accent mark retained it when attaching to a single personal pronoun (cogió, cogióle; dé, déle). Since 2010 this verbal forms follow the general rules to write accent mark: cogió, cogiole; dé, dele.
  • If a monosyllabic or aguda polysyllabic verbal formis attached to two personal pronouns, the accent mark is written on the stressed syllable: dímelo, decídselo, dáselo.
  • If a llana or esdrújula verbal form is attached to one or more personal pronouns, the accent mark is written on the stressed syllable: permita, permítaseme; coge, cógelo. So the esdrújulas and sobrestrújulas verbal forms are always marked with an accent sign: búscalo, diciéndome, míralo, ríase, antojósele.
  • In Spanish, the adverbs ending in –mente are the only words with two stressed syllables. The first syllable of -mente always sounds stressed, but it is never marked on. We write accent mark on the adjective if it is required: tonta, tontamente; cruel, cruelmente; tímida, tímidamente. When two words are attached to forma compound word, the stressed syllable of the last one receives accent mark. The word bears accent mark according to the former rules: germanosoviético, hispanofrancés.
  • We write accent mark on the capital letters, according to general rules of accentuation.
  • The Latin terms bear accent mark acording to the rules for the Spanish words, except if they are part of ascientific names: ítem, ex cáthedra, ante méridien; but Betula pendula, Cichorium intybus.
    The words taken from another language also using Latin alphabet are written according to the original form: Wagner, Henry James.
    The nouns transliterated from other alphabets bear accent mark according to the general rules for Spanish words: Antón Chéjov, ayatolá.
    We also write accent mark on the geographical names incorporated into Spanish: París, Moscú.