A number of Tibeto-Burman languages exhibit morphological ergative alignment, while others clearly do not. In these languages, matters of information structure determine core argument marking. Specifically, both A and S marking may be used to indicate topic, contrastive topic, broad focus, and/or contrastive focus. It is most often A or S, not P, that is assigned such status and between A and S, it is most often A that takes marking. Preference for topic or focus marking on A creates the impression of ergative alignment, but an ergative alignment analysis is untenable as S may be marked under the same conditions and with the same morpheme as A. Considerations of discourse-level clause interpretation in Tibetan, Meitei, and Burmese show that information structure not transitivity determines A and S marking. The presence or absence of marking based on information structure is characterized as “unique differential marking”, distinguishing it from the differential marking observed in ergative and accusative alignment systems.
Do contrastive topics exist?
