Contemporaneous Comparative Corpora and Historical Linguistic Reconstruction

A comparison of two large oral corpora, one Nigerian Arabic, one Egyptian, show a massive expansion, both quantitative and structural-functional, of the demonstrative in Nigerian Arabic. Contact with other languages of the Lake Chad area, into which Arabic speakers began to move about 1215 CE, explains the innovations in the use of the Nigerian Arabic demonstrative. Straightforward comparison of corpora offers lucid insights into basic historical linguistic questions such as contact-based vs. internal change, the relation between contact and simplification, and how contact-induced changes integrate into inherited systems. Because of its extensive linguistic history and wide dispersion, Arabic is particularly well suited to such investigations.