In this dissertation, I investigate the syntax of A′-dependencies (wh-movement, focus movement, relativization and topicalization) in Bamileke Medumba, a Grassfields Bantu language spoken in the Western Region of Cameroon. I first examine the in-situ/ex-situ partition with Medumba wh-/focus construals and propose an analysis in which the necessity of movement is driven by interpretation. This approach correctly predicts structural and semantic differences between in-situ and ex-situ wh-questions and foci in Medumba. Thus, they differ in Medumba with regard to: (i) exhaustivity –– in that in-situ wh-questions and foci are non-exhaustive whereas their ex-situ counterparts are exhaustive –– (ii) question-answer pairs –– in that the information-theoretic structure of the answer must match the information-theoretic structure of the question –– and (iii) fragment answers –– in that fragment answers to in-situ wh-questions are not focus-marked whereas fragment answers to ex-situ wh- questions are focus-marked. I also examine A′-agreement, analyzed as the reflex of Phasal-Agree. I show that A′- agreement is not only a crucial diagnostic for A′-movement, for Phasal-Agree and for the locality of movement (cyclic phase-by-phase movement (Biberauer and D’Alessandro 2006; Chomsky 2000, 2001; van Urk 2015; van Urk and Richards 2015)) but also a diagnostic for intermediate phases. Finally, I examine resumption in Medumba A′-construals. Resumptive pronouns in Medumba surface both in island violation contexts (including apparent complement CPs analyzed as disguised adjunct clauses) as well as in contexts where there is absolutely no island violation
(root clauses), where they alternate with gaps. I argue that resumptive structures are derived in Medumba via the economy principle of Last Resort (Koopman and Sportiche 1986; Rizzi 1990; Chomsky 1991, 1998; Shlonsky 1992; Bobaljik 1995, Lasnik 1995; Ura 1996; Pesetsky 1997; Collins 2001; Bošcović 2011). To get a unified account of resumptive structures in Medumba, I propose that Last Resort is conditioned by syntactic and semantic constraints. Syntactic Last Resort derives resumptive pronouns in Medumba island violation contexts, to salvage A′- dependencies that would otherwise result in ungrammaticality. Semantic Last Resort is a condition on interpretation that derives resumption in configurations that would otherwise result in ambiguity.