Maarten Kossmann has uploaded his preliminary classification of Berber varieties based on shared innovations: Berber subclassification (preliminary version). He divides Berber into seven blocks:
- Zenaga block (Zenaga of Mauritania, Tetserrét in Niger)
- Tuareg block
- Western Moroccan block (SW Morocco, Central Morocco, i.e. Tashelhiyt and
most of Tamazight)
possibly including NW Moroccan Berber (Ghomara, Senhadja de Sraïr)
- Zenatic block (Eastern Morocco, Western Algeria, Saharan oases, Tunisia, Zuara) extending towards the east with Sokna, Elfoqaha, Siwa
- Kabyle (N Algeria), possibly linked to the western Moroccan block
- Ghadames (Libya), probably to be linked to Djebel Nefusa (Libya)
- Awdjilah (Libya)
The most interesting Kabyle varieties for historical reconstruction are the little-known ones of the extreme east, "Tasahlit". As it happens, Abdelaziz Berkai has just uploaded his recent thesis, a dictionary and sketch grammar of the Tasahlit of Aokas: Essai d’élaboration d’un dictionnaire Tasaḥlit (parler d’Aokas)-français. The quality of his work appears excellent, and this will no doubt be a very useful resource. The choice of dialect, however, is not entirely ideal. It is clear from Basset's dialect atlas, and from the all too rare comments in Rabdi's grammar on neighbouring varieties, that the vocabulary of Aokas is still quite close to that of Bejaia; the really divergent varieties seem to be those of the Babor Mountains and Oued el Bared, approaching Jijel, and those are the ones most likely to give an insight into the dialect of the now largely Arabised Kutama.
I haven't yet had time to properly look at Samir Ben Si Said's thesis, De la nature de la variation diatopique en kabyle: étude de la formation des singulier et pluriel nominaux, but it tackles the synchronically as well as diachronically thorny problem of Berber non-concatenative morphology, and argues for an approach based more on roots than on stems, contrasting with another important study I've been working through lately, Heath's Grammar of Tamashek (Tuareg of Mali).