Schwa realisation in verbal inflection in two dialogue registers of German spontaneous speech

Word-final schwa in German inflectional suffixes shows varying realisations in spontaneous speech – from full realisations with varying duration to no realisation. While previous research has identified numerous social, distributional, and grammatical factors influencing the variation of phonetic variables in general, it remains unclear how fine-grained functional differences in different registers specifically affect schwa realisation. In this corpus-based study, we compare schwa realisation in two dialogue registers of German spontaneous speech – free conversation and task-based dialogues – which differ only in their communicative goal and therefore have different functional requirements. We find that schwa is rarely realised, though slightly but significantly more often in free conversation than in task-based dialogue. Other factors also promoting schwa realisation across both situations are less frequent verbs and sequences, and IP-final position.