In Chapter 7, we discuss expressions, constituting the ‘lowest’ unit of analysis in our model. We here focus specifically on pragmatically salient conventionalised expressions indicating the interactants’ rights and obligations in a particular context. We propose an analytic procedure by means of which such expressions can be systematically compared by using large corpora. As a case study, we examine Chinese and British English expressions. We focus on expressions popularly associated with the speech acts Request and Apologise. We examine groups of expressions with an increasing degree of complexity.