When we speak, we convert a message from a conceptual idea into a string of words. Several processes are involved in sentence production: the selection of a conceptual message, lexical selection, grammatical encoding, phonological planning, and articulation. We are particularly interested in the processes that allow for the construction of syntactic structures, as in everyday communication we effortlessly organise our speech into relatively complex syntactic structures. During grammatical encoding, in particular, lexical items are assigned a function and organised into a hierarchical structure. Our goal is to shed light on the neural correlates of these unification processes in production. Since the respective processes during comprehension have been extensively studied using neuroimaging methods, we additionally aim to compare the syntactic networks during production and comprehension.