The purpose of this chapter is to show that the model of Functional Discourse Grammar can be used to provide a detailed classification of expressions of negation by taking its hierarchical, layered structure as the point of departure. The chapter thus follows up on ideas first launched in Dik (1997) concerning the various layers of Functional Grammar at which polarity operators can apply. FDG has introduced a number of additional layers which can also host the negative operator to those recognized in FG, and it has furthermore introduced the distinction between the Representational (semantic) and Interpersonal (pragmatic) Levels. We will argue that operators with a negative value can be found at all layers of both the Interpersonal and the Representational Levels. We illustrate all these types and show how their scope properties and their formal manifestation and behaviour warrant their identification in the grammar.