Appendix:Catalan orthography

Catalan orthography is based on the spelling of Latin. It has also developed some other idiosyncracies in the way certain combinations of sounds are spelled.

Accents
Catalan spelling requires that the placement of the stress be predictable from the written form. Accents are placed on vowel letters to indicate this. There are also rules that dictate where the stress should be placed by default. If the word follows these rules, no accent is written.

If no accent is written, then the stress is placed as follows. The last vowel of a word is stressed, except: When any of those exceptions apply, the second-last vowel of the word is stressed. However, an i or u that occurs between two vowels doesn't count as a vowel itself, because it is pronounced as a consonant.
 * When it's the last letter of a word
 * When it is followed by only -s.
 * When it is i or e followed by -n.

These rules have consequences for the inflection of verbs, nouns and adjectives as well. If a verb has a stem ending in -s or -n, then an accent will need to be placed on the last syllable when there is no ending, to indicate that it is to remain stressed. In nouns and adjectives, attaching an ending may cause the removal or addition of an accent.

Diacritics
Because of their predictable stress are never accented, with the exception of the following 15 words (and their derived forms) which take a  to avoid.

Situation before 2016
Before the 2016 spelling reform, the list of words differentiated with diacritics was considerably larger (around 50, not including derived forms). According to the 2016 orthography, those older spellings are now only admitted for metalinguistic transcriptions or when the intended meaning is not clear from the context.

See ca:Categoria:Mots en català amb accent diacrític for a more complete list.

Alternation of consonants depending on the following vowel
Consonants representing velar or palatal consonants have different pronunciations depending on the following vowel. Therefore, the spelling often changes when the following vowel does, to preserve the pronunciation.

Diaereses
A is placed on a vowel, usually ï or ü, to indicate that it is pronounced separately and counts as a separate syllable for stress placement rules. Or to phrase it phonetically: it indicates that the letter is to be pronounced as a vowel or  rather than a semivowel  or. For example, has three syllables, in which the penultimate is stressed:. Meanwhile, the similar form lacks a diaeresis, so it has only two syllables, with stress on the first:.

In verbs, this typically affects the present subjunctive, which ends in -i. In verbs of the second and third conjugation, it also affects the imperfect (-ia) and in the third conjugation also some present tense endings. The diaeresis is used to prevent it from becoming a. If the stem of the verb itself already ends in a semivowel (as in ), then it is dropped altogether. The case of is special, because it already has a diaeresis in the stem. In that case, the rule is that when two diaereses come together, the diaeresis is written only on the second vowel, so üï -> uï by this rule.

Restrictions on the placement of consonants
The following changes apply mostly to adjectives, and to the 2nd and 3rd person singular present tense forms of verbs in the second conjugation, and some in the third (the ones without the -eix- infix).

Voiced consonants (b, d, g) that follow a vowel cannot appear at the end of a word, so they are devoiced when they appear at the end of a word, or before a final voiceless consonant. There are no examples of verbs with stems ending in g, but many second conjugation verbs have a so-called "velar infix" -g- which appears in many of the forms as an extension of the base stem. If this infix appears in the first-person singular present indicative form (as it often does), it undergoes devoicing as well.

The sounds l and r can't stand between two consonants, or between a consonant and the end of a word. An extra -e- is inserted to ease pronunciation. (Here, C stands for any consonant. But note that while -rr- counts as two consonants, -ll- only counts as one.)

The sound s cannot follow another s or an s-like sound (a sibilant). An extra vowel is inserted to compensate. This vowel is -e- in verbs, but it is usually -o- in masculine nouns.

In addition, ss and j can't stand at the end of a word, and are changed to s and ig.