Read this: The process of morphological derivation in Catalan follows the same principles as the other Romance languages, where agglutination is common. Many times, several affixes are appended to a preexisting lexeme, and some sound alternations can occur, for example elèctric [əˈlɛktrik] ("electrical") vs. electricitat [ələktrisiˈtat]. Prefixes are usually appended to verbs, for as in preveure ("foresee").
Now answer this question, if there is an answer (If it cannot be answered, return "unanswerable"): What other word changes can occur in derivations?
sound alternations