Model: erwerben
Auxiliary: sein
Other forms: nicht verderben
Irregular congugation: replacement of -e- in the stem of Present tense with -i- for the second and third person singular form of Present tense and singular form of Imperative, and with -a- for the Preterite ("ich erwarb") and with -o- in Past Participle ("erworben").
Präsens
Präteritum
Futur I
Perfekt
Plusquamperfekt
Futur II
zu + Infinitiv
