According to their function in the sentence, the adjectives can be:
1. ATTRIBUTIVE, when they stand next to a noun —> Anna ha una grande casa / Anna has a big house
2. PREDICATIVE, when they are used as the complement of the verb essere (to be) [or similar verbs, as diventare (to become)] —> Anna è simpatica / Anna is nice
3. ADVERBIAL, when they modify the meaning of the verb —> Anna corre forte / Anna runs quick —> NOTE that in this function, all adjectives become invariable (you use only the masculine singular form)
Examples:
- Marco ha un cavallo veloce / Marco has a fast horse —> (attributive)
- Mariangela ha una sorella simpatica / Mariangela has a nice sister —> (attributive)
- Marco è antipatico / Marco is nasty —> (predicative)
- Quando ha fame Marco diventa antipatico / When he is hungry Marco gets nasty —> (predicative)
- Mangia piano! / East slow! —> (adverbial)
- Marco deve imparare a scrivere chiaro / Marco must learn how to write clearly —> (adverbial)
