Chapter 9 offers a summary of findings and general conclusions with regard to (1) evidentiality in English, (2) constructions, interactions, and change, (3) the House of Commons as a community of practice in change (and Prime Minister’s Questions as an activity in change), and (4) the potential for a new research strand, Diachronic Interactional (Socio-)Linguistics.

Chapter 4 describes the composition of the self-compiled data base for the study, which consists of two comparable data sets of authentic recordings of Prime Minister’s Questions (PMQs) from 1978–1988 (audio) and 2003–2013 (video) as well of the respective Hansard files. It outlines how the language-external processes which have changed the interaction at PMQs between 1978–2013 provide the backdrop against which the evolution of reported speech is analysed. Specifically, it is argued that the composition of participation in the activity at PMQs has changed in correlation with the more prominent role of the Leader of the Opposition, and fostered a sharp increase of reported speech. It is demonstrated how the calculation of frequencies is conducted in relation to turn types and speaker roles. The chapter finally presents the transcription conventions and procedure, and discusses the basic methodological assumptions of the study.