Caught in the middle

The relationship between the Songhay and Mande language families has fascinated West Africanists. The typological similarities run deep, but the respective lexicons are noncognate. I focus here on a typological rarity, a bidirectional case marker (BCM), namely Proto-Songhay *nà and its descendants, and argue that it was most likely borrowed from Mande as part of the adoption by Songhay of the equally typologically rare Mande-type S(‑infl)‑O‑V‑X syntax, which reduces to S‑O‑V‑X when there is no post-subject inflectional morpheme (predicative marker). Apparently Songhay had little choice but to borrow the morpheme on the grounds that it did not previously possess the S(‑infl)‑O‑V‑X construction of which it is a key component, especially since a buffer between S and O prevents real-time mis-parsing of two adjacent NPs as possessor-possessum. The medial (‘caught in the middle’) position of the morpheme in the S‑BCM‑O sequence favored the borrowing, in spite of its abstract relational function which in some theoretical models should block borrowing.