For example, overhear is the same as hear: overhear - overheard - overheard. We left out rarely used words you will hardly hear today like shoe - shod - shod.īesides, if we add a-, be-, for-, in-, inter-, mis-, off-, out-, over-, pre-, re-, un-, under-, up-, with- to the infinitive of an irregular verb, its past forms will stay the same. Are these really all existing irregular verbs?