The current book consists of 177 pages of primary text, divided into six chapters: the first is an introduction (pp. 1–15) and the last a set of conclusions (pp. 171–7). In between there are four chapters, two explicitly on new dialect formation (pp. 16–56 and pp. 57–105 respectively), one on linguistic contact and near-relative relationships (pp. 106–23) and one on the development of English in the late Old English and early Middle English periods (pp. 124–70) during which the language would appear to have undergone considerable typological change. The consideration of closely related varieties is central to this book, as the author states: ‘many of the authorities on linguistic contact do not discuss overtly or at length what happens when closely related varieties come into contact with each other. . . This book is designed to redress this imbalance. . .’

In today's publishing world there is a widespread insistence on general titles, which means that the real topic and scope of a book are often to be found in its subtitle. This is clearly the case with the present book, Contact, which, while having a 16-page introduction to the topic of language contact discussing primarily the views of Sarah Thomason found in her 2001 book, essentially deals with the process of new dialect formation, albeit against a background of language contact. This historical process for overseas forms of English is examined by the author with particular reference to the deterministic views of Peter Trudgill, which were stated most dogmatically in his 2004 monograph. In his consideration of Trudgill's model, McColl Millar discusses the origins and shape of New Zealand English in some detail. He is in general favourable towards this model and omits to mention instances where Trudgill was shown to be wrong, e.g. in his assumption that relative inputs to early New Zealand English accounted for the fact that it is an /h/-ful variety today. This has been shown by Elizabeth Gordon (see Gordon Reference Gordon and Hickey2010) to be due to prescriptivist attitudes in early New Zealand white society. However, McColl Millar does mention critical stances and to his list of dissenting views from Trudgill's deterministic model of new dialect formation should be added Hickey (Reference Hickey and Hickey2003), especially as he explicitly addresses the issue of linguistic identity (p. 34). And McColl Millar does state, later in the book, that ‘[p]ersonal and social identities do appear central to the formation of new varieties of a language, a view apparently counter to many of Trudgill's views on the issues involved’.

Chapter 3 of this book, entitled ‘New dialect formation and time depth’, is dedicated almost entirely (for some 37 pages, pp. 59–96) to the description and analysis of language development on the Shetland and Orkney islands. This chapter is, in the view of this reviewer, the most successful part of the book. Not only is the level and depth of historical and linguistic discussion much greater than elsewhere, but the author is clearly aware of the multiple causations for the rise of specific forms of Scots on these islands. He considers the tabula rasa situation for English on the islands similar to that on Tristan da Cunha referred to earlier in the book, examines its early forms in the light of Salikoko Mufwene's founder principle (Mufwene Reference Mufwene1996) and discusses the contact with Norn, the form of Old Norse which survived on the islands and part of the Scottish mainland down to early modern times.

The author of the present book is an authority on Scots (see McColl Millar Reference McColl Millar2007) and has written widely on historical sociolinguistics (see McColl Millar Reference McColl Millar2005, Reference McColl Millar2010, Reference McColl Millar2012). This lends the treatments of Scottish topics in the book particular authority, such as the discussion of Glaswegian Scots and Scottish Standard English. His qualifications for writing on new dialect formation and the history of English are equally evident. However, the book is curiously out-of-date in terms of acknowledging and processing more recent literature on language contact. Thus the reference work Hickey (Reference Hickey2010) is not quoted, nor is Nevalainen & Traugott (Reference Nevalainen and Traugott2012), which has a dedicated section on language contact. In quoting literature on new dialect formation, McColl Millar refers to the assumed process of swamping (p. 104, earlier referred to on pp. 38–40), following a term introduced by Roger Lass in the 1980s who maintained that sheer numbers of speakers in a new dialect formation scenario determine the later shape of a variety. But the author does not critically reflect on the lack of differentiation which this term implies and does not dwell on more recent models for the formation of varieties, such as Irish English or Glaswegian Scots, despite the fact that he does discuss the Dynamic Model by Edgar Schneider (Reference Schneider2003) earlier in the book (pp. 17–23).

In summary one can say that this book provides much food for thought and reflection on the processes of dialect contact and new dialect formation despite the absence of many germane works on contact and variety formation. Furthermore, some of the discussions are very general, without any discussion of linguistic features possibly traceable to contact, e.g. the various references to English-Celtic contact in the early centuries of Germanic settlement in Britain (in chapter 5 ‘English in the “transition period”: the sources of contact-induced change’). Nonetheless, the book reads well and the author displays wide knowledge of the topic, discussing many scenarios, above all in Celtic regions of Britain and Ireland, which are not considered in mainstream works on language contact.