A fundamental question for syntactic theory concerns the nature of the basic computations that are used to construct grammatical representations. This chapter is devoted to a framework, Tree Adjoining Grammar (TAG). TAG is a formalism that builds grammatical representations through the composition of smaller pieces of syntactic structure. The interest of TAG for linguistic theory comes not only from the prominence it assigns to structural recursion, but also from the perspective it offers on the nature of syntactic dependencies. The author explores the implications of TAG for the nature of the grammar, specifically in the domain of long-distance dependencies. The use of TAG in syntactic theory is also motivated by questions of formal complexity. The author explores the role that TAG can play in discussions of the computational constraints on grammar. Chomsky adopted a more powerful system for grammatical representation, one incorporating grammatical transformations.