The main focus of this talk is the recent investigations on relative clause constructions (RCCs) in Turkish Sign Language (Türk ??aret Dili - T?D). I first introduce relativization strategies that have been identified in different sign languages in literature. Next, I discuss RCCs in T?D. In particular, I present several relativization strategies and their frequency of distribution in a smallscale corpus consisting of narrative data (Kubus 2016). Signers of T?D prefer both internally headed and externally headed relativization strategies. They use non-manuals (i.e. facial expressions including squinted, brow raise or slight-headshake) as well as manual signs (i.e. clause final INDEX sign, AYNI ‘same’ or different combinations of them) for marking relative clauses in T?D. I also discuss the dynamics of the variation of these markers with respect to local and global aspects of discourse structure, i.e. the position of head nouns (Kubus & Nuhbalao?lu, 2018a) and the information status of head nouns (Kubus & Nuhbalao?lu, 2018b). The ongoing empirical investigation of relativization strategies in T?D at different levels suggests that some markers of RCC's in TID are in the process of grammaticalization. Finally, I will also discuss various challenges in investigating relative clause constructions in sign languages.