Shene Othman Hassan submitted her thesis on Syntactic and semantic aspects of supplementary relative clauses in English and Sorānī Kurdish and defended it December 18. Congratulations!
Shene looks at two understudied types of supplementary (i.e. non-restrictive) relative clause in English: those introduced by determiner-which, see (1), and those introduced by that, as in (2).
(1) Maybe people will attack me, in which case I will attack back. (COCA)
(2) The Patas monkey, that spends almost all of its time in open grassland,
adopts just such tactics. (Huddleston & Pullum, 2002: 1052)
Shene uses these two types of relative clauses to develop a new analysis of the English relative clause system. Shene extends this analysis to relative clauses in Sorānī Kurdish.