This book proposes a theory of the distribution of adverbial adjuncts in a Principles and Parameters framework, claiming that there are few syntactic principles specific to adverbials; rather, for the most part, adverbials adjoin freely to any projection. Adjuncts' possible hierarchical positions are determined by whether they can receive a proper interpretation, according to their selectional (including scope) requirements and general compositional rules, while linear order is determined by hierarchical position along with a system of directionality principles and morphological weight, both o.