Acquiring novel words and their past tenses: Evidence from lexical effects on phonetic categorisation

► We present new evidence on the acquisition of novel spoken verbs. ► Both immediately and a week later phonetic categorisation was biased by new forms. ► Biases occurred with unheard past tense forms, indicating morphological generalisation. ► Biases in reaction time only occurred a week later. ► Results indicate that novel word lexical behaviours occur at different time points.