Constituentless Compositionality: A Compositional Account of Dependency Grammar Ryan Nefdt Abstract: In this research, I investigate the principle of compositionality from a formal linguistic point of view. I describe the natural language debate surrounding the principle and argue against the usual reasons in its favour according to systematicity, productivity and linguistic infinity. I then discuss the principle with relation to the formal languages used in modeling natural languages. I argue that the principle is valid in this domain of abstraction only given complexity and infinity issues. Finally, I attempt to provide a compositional treatment of a non-constituency based grammar formalism, dependency grammar, using underspecification and head semantics