In the 1990s as historical studies of grammaticalization proliferated and questions arose about the relationship between it and lexicalization, we independently sought to understand better to what extent efforts to maximize the distinctions between the two were justified. At the International Conference on English Historical Linguistics in Santiago de Compostela, September 2000, we discovered that we had somewhat similar concerns and similar ideas, most especially that we were both embracing the realization that what we had polarized (see Hopper and Traugott 1993, 2003; Traugott 1994; Brinton 2002, and, to a lesser extent, Traugott 2005) were in fact very similar in certain respects. Having taken criticisms in Cowie (1995) to heart, Traugott was also concerned about the status of derivation in grammaticalization and lexicalization. Meanwhile, it became clear that many others were making similar efforts to account for the similarities as well as differences between the two processes (e.g., Lehmann 1989, 2002; Ramat 1992, 2001; Wischer 2000; Heine 2003b). The diversity of points of view on the two topics has been a matter of frustration to some, but we view it as an inevitable step in the development of relatively new subfields of linguistics, much as has occurred in the study of syntax or morphology.

Consistent with the aims of this series, Cambridge Research Surveys in Linguistics, our purpose in this book is to bring together a variety of scholarly debates concerning the relationship between lexicalization and grammaticalization in language change, with focus on the former.