The first descriptive and normative grammar book of modern Catalan was written by Pompeu Fabra in 1918. In 1995, a new grammar by Antoni Maria Badia i Margarit was published, which also documents the Valencian and Balearic varieties.
The grammar of Catalan follows the general pattern of Western Romance languages. The primary word order is SVO (subject–verb–object).
Substantives and adjectives are not declined by case, as in Classical Latin. There are two grammatical genders—masculine and feminine.
Grammatical articles developed from Latin demonstratives. The form of the article depends on the gender and the number of the subject and the first sounds of the word and can be combined with prepositions that precede them. A unique feature of Catalan is a definite article that may precede personal names in certain contexts. Its basic form is en and it can change according to its environment: en Joan meaning ‘John’, na Maria meaning ‘Mary’ (note clitic en has also other lexical meanings). One of the common usages of this article is in the word can, a combination of la casa shortened to ca (‘house’, as French chez) and en, which here means ‘the’. For example la casa d’en Sergi becomes can Sergi meaning ‘the house of Sergi’, ‘Sergi’s house’. Note here, other definite articles (el, la, els, les) can also be used with personal names like in Portuguese, as la Maria (‘Mary’, Portuguese a Maria).
Verbs are conjugated according to tense and mood similarly to other Western Romance languages. Present, imperfect and simple preterite are based on classical Latin present, imperfect and perfect respectively, future and conditional are formed from the infinitive followed by the present and imperfect form of the auxiliary verb haver (written together and not considered periphrastic). Periphrastic tenses are formed from the conjugated auxiliary verbs haver (‘to have’) and ésser (‘to be’) followed by the past participle. A unique tense in Catalan is the “periphrastic simple preterite,” which is formed of vaig, vas (or vares), va, vam (or vàrem), vau (or vàreu) and van (there is the usual wrong idea these forms are the conjugated forms of anar, which means ‘to go’), which is followed by the infinitive of the verb. Thus, jo vaig parlar (or more simply vaig parlar) means ‘I spoke’.
Nominative pronouns are often omitted, as the subject can be usually derived from the conjugated verb. The Catalan rules for combination of the object pronoun clitics with verbs, articles and other pronouns are significantly more complex than in most other Romance languages; see Weak pronouns in Catalan.