Semantics circle: What makes a necessity modal in Indonesian strong vs. weak?

Abstract

Joint work with Hiroki Nomoto, David Moeljadi, and Sarah Zobel

In this paper, we investigate the semantics of Indonesian (Austronesian) modals harus, mesti and their derivatives based on the Indonesian subcorpora of MALINDO Conc (Nomoto et al. 2018) as well as elicitation.We aim to answer the following research questions. 
    [1] Previous descriptions suggest that harus and mesti 'must' express strong necessity whereas their affixed forms (se-)harusnya and (se-)mestinya express weak necessity. Further, previous descriptions suggest that harus and derivates only express root modal flavour (i.e., non-epistemic), while mesti and its derivatives can express both epistemic and root modal flavours (e.g., Alwi 1992; Sneddon et al. 2010). Can these qualitative descriptions be validated quantitatively? Preview: Mostly yes; we find that mesti, harus and its derivatives are compatible with epistemic modality, and -nya vs. se-...-nya derivatives do not differ semantically. 
    [2] In the related language Javanese, no dedicated counterfactual (CF) morphology exists, necessity modal expressions lack gradability and the suffix -ne used in weak necessity modals is incompatible with possibility modals (Vander Klok & Hohaus 2020). Do these properties constitute a typological cluster? Preview: No. While Indonesian has no CF morphology and (se)-...-nya does not attach to possibility modals, we find that (weak) necessity modals are gradable. Based on these new empirical insights, we present an analysis, following Portner & Rubinstein's (2016) gradable analysis for English weak necessity