I-XVI -- 1 Introduction -- 2 Theoretical, methodological and empirical foundations -- 3 HAVE GOT TO/GOTTA and HAVE TO/HAFTA -- 4 WANT TO and WANNA -- 5 Models and motivations for emerging English modals. 5.1 Chapter outline -- 5 Models and motivations for emerging English modals. 5.2 Frequency -- 5 Models and motivations for emerging English modals. 5.3 Mechanisms and pathways of change -- 5 Models and motivations for emerging English modals. 5.4 Towards a model for natural change in spoken and written text types -- 5 Models and motivations for emerging English modals. 5.5 The marginal modals NEED (TO), OUGHT (TO) and DARE (TO) -- 5 Models and motivations for emerging English modals. 5.6 Motivations -- 5 Models and motivations for emerging English modals. 5.7 Gravitation and categorization -- 5 Models and motivations for emerging English modals. 5.8 Some implications of the gravitation model -- 6 Conclusion -- Notes -- Appendices -- References -- Index