Chapter 5 looks at hidden reflexes of Proto-Afroasiatic language features in Central Chadic which have hitherto largely gone unnoticed. These are in particular the fundamental root-and-pattern structure, the relatively high frequency of triradical roots, the structural relevance of ‘weak radicals’ that function as both consonants and high vowels, the sporadic local emergence of synchronic glottalised consonants, the synchronic presence but historical absence of prenasalised obstruents, the high frequency of the reconstructable polyfunctional prefix *{ma-}, and the remnants of a set of determiners as reconstructed for Proto-Chadic by Schuh (1983).

Chapter 2 deals with methodological preliminaries and introduces the central theoretical concepts. It begins by outlining the extra-linguistic historical background regarding the present habitat of Central Chadic languages. It identifies the exceptional typology of Central Chadic languages, in particular regarding their enigmatic vocalic domain. The chapter introduces the problems of applying the classic comparative method and explains the value of internal reconstruction. It discusses problems of dealing with various formats of data transcription, and it introduces central notions such as vowel epenthesis, weak radicals, vocalisation, and prosodies. Finally, it positions the current study against the background of previous studies on the subject.