In this monograph, the nature of processing strategies is explored in some detail, with an attempt to cut through the maze of often contradictory and confused proposals concerning the nature and form of various strategies. Once a preliminary conception of the nature of cognitive strategies and a hypothesis of how they interact with linguistic structures has been reached, it will be explored how such strategies are employed by examining experiments which address the role played by certain of these strategies in the comprehension and production of sentences. The authors draw a distinction between a strategy on the one hand and a grammatical structure on the other. They argued that, in principle, strategies ought to be formulated as language-independent, cognitively based operations which are involved in cognitive domains other than language, but which, in language processing, interact with language-specific structures to facilitate processing. Moreover, strategies are not linguistic rules, since, unlike rules, they permit exceptions and express tendencies rather than firm yes-no choices.