This dissertation is an investigation of two interrelated clausal left edge properties in the Spanish syntax: the positional effects of left edge elements (akin to the Tobler Mussafia and Wackernagel effects) and the availability of constituent dislocation. I focus on the syntax of preverbal lexical subjects and their relation to the several positions in the clause. Based on the projectionist approaches developed by Rizzi (1997), Poletto (2000), among others, this dissertation sketches a more reduced version of the complementizer system dubbed the Narrow Left Edge. Accordingly, the left periphery is composed by two core projections: the Point of View Projection (CP) and the Assertion Projection (c*P). In particular, I claim that the phenomenon of second position placement is manifested in Modern Spanish (cfr. Su�er 1994 and Fontana 1993) and must be related to the licensing of the c*P projection in declaratives and nondeclaratives. In addition, the mechanics of word order dislocation shows that constituents can be displaced to the left edge by movement or by base generation. These two effects can be explained if an Agree relation is postulated between the Assertion Phrase c*� in the lower left edge, and T� in the inflectional layer.