The aim of this set of study- and worksheets is to help (adult) students memorize very common irregular verbs according to given categories because of 1) the form of the infinitive vs. both the simple past and past participle irregular forms and 2) the similar vowel changes. [Translations of the infinitives into Catalan are provided. You can easily erase them and just leave blanks or translate them into any other language, though, since I am uploading a Word version.] I hope somebody else finds it useful!