Functional trade-off between lexical tone and intonation: typological evidence from polar-question marking

Tone languages are often reported to make use of utterancelevel intonation as well as of lexical tone. We test the alternative hypotheses that a) the coexistence of lexical tone and utterance-level intonation in tone languages results in a diminished functional load for intonation, and b) that lexical tone and intonation can coexist in tone languages without undermining each other’s functional load in a substantial way. In order to do this, we collected data from two large typological databases, and performed mixed-effects and phylogenetic regression analyses controlling for genealogical and areal factors to estimate the probability of a language exhibiting grammatical devices for encoding polar questions given its status as a tonal or an intonation-only language. Our analyses indicate that, while both tone and intonational languages tend to develop grammatical devices for marking polar questions above chance level, tone languages do this at a significantly higher frequency, with estimated probabilities ranging between 0.88 and .98. This statistical bias provides cross-linguistic empirical support to the view that the use of tonal features to mark lexical contrasts leads to a diminished functional load for utterance-level intonation.