⇒ Apart from a very few cases where the diaresis (e.g. ü) is used, there is only one written accent in Spanish (á) and this is used in the following circumstances:

• To show that a word does not follow the rules of natural stress;
• To differentiate between words which are spelt the same;
• In interrogatives and exclamations

⇒ If a word ends in an -n, -s or a vowel, the stress naturally falls on the penultimate (last but one) syllable:

⇒ If a word ends in any other sound, the stress naturally falls on the last syllable:

⇒ Words that follow these rules of natural stress do not require a written accent (or stress mark), but if the word is pronounced in a way that does not follow these natural rules then a stress mark must be put on the vowel in the stressed syllable:

⇒ Some words require a stress mark in the singular but not in the plural, since by making the word plural it now ends in an -s, resulting in the natural stress now falling on the appropriate syllable: inglés - ingleses

⇒ The situation outlined above is fairly straightforward, but when two or more vowels occur together in a word you will need to understand the rules about diphthongs in order to work out the stress.

• A diphthong is a sound made by combining two vowels

⇒ Vowels are divided into strong and weak vowels – a, e and o are 'strong' vowels and u and i are 'weak' vowels

⇒ When a weak vowel occurs together with another vowel, they form a diphthong, which counts as only one syllable

⇒ If the weak vowel is next to a strong vowel, the stress falls on the strong vowel e.g. piedra (stone) has two syllables: pie-dra

⇒ If both vowels are weak, the stress falls on the second vowel in the diphthong e.g. viuda (widow)

⇒ If, however, two strong vowels occur together they form two separate syllables e.g. ateo (atheist) has three syllables: a-te-o

⇒ Sometimes stress marks are used to differentiate between two words that are spelt and pronounced in exactly the same way:

⇒ When certain words are used as interrogatives (questions) or exclamations they require a stress mark, whereas they do not require a stress mark in other circumstances: