This dissertation establishes the syntactic representation and derivation of relative clause (RC) constructions in Bizkaiera Basque. Using native speaker introspection, grammaticality judgment under direct elicitation and formal experiments, I show that Bizkaiera follows the Head raising strategy in RC construction. Evidence for this comes from idioms, scope interaction and quantifier binding. These tests focus on the existence of a local relationship, internal to the RC, between the Head and the elements in the RC. Detecting such local relation, I conclude that the Head of the RC was inside the RC. A problem for the Head Raising Analysis is that morphologically rich languages show that the Head share the Case of the external D and not that of the internal D, which would be expected if there were Head raising (Borsley 1997). I propose the "[subscript D]Case Valued u-Feature Precariousness Condition," which establishes that a DCase (the one assigned by T or v) valued u-feature is "precarious" until it is sent to Spell-Out and therefore, the value is visible for further targeting by a c-commanding Probe. In a RC with a DP Head, the external D copies the DCase and phi-features of the internal D. Since the DCase valued u-feature of the external D is precarious because it has not been spelled-out yet, it is targetable by a c-commanding Probe (T, v, P in the main clause). When a Probe Agrees with the external D, the Goal obtains a new Case value, which is the Case value that is spelled-out for being the last one that the external D has received. The DCase Valued u-Feature "Precariousness" Condition is supported by the observation that the DP extracted out of an [-Q] embedded clause gets its DCase valued u-feature re-valued when it Agrees with a higher nu in the Spec-nuP configuration. Furthermore, I identify two micro-dialects within Bizkaiera Basque: A PP Headed RC under a matrix ergative or absolutive Case is grammatical in micro-dialect A and ungrammatical in micro-dialect B. I claim that the difference between the two micro-dialects relies on the status of their P: in micro-dialect A the P is a Probe with unvalued D and phi-features, while in micro-dialect B the P is a Probe with just an unvalued D-feature. In a PP Headed RC, in micro-dialect A the external D copies the PCase and phi-features values of the internal P allowing it to value the phi-features of the Probe T/nu. In micro-dialect B, due to the lack of phi-features in P, the external D only copies the PCase of the internal P, which makes it not capable of valuing the unvalued phi-features of the Probe T/nu, therefore, the derivation crashes. The presence of phi-features in the P of micro-dialect A as well as the lack of them in the P of micro-dialect B can be observed in a long distance extraction: in micro-dialect A a higher nu can obtain its unvalued phi-features valued by Agreeing with the extracted PP, whereas in micro-dialect B it cannot do so. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]