A study of the structural side of a common practice among bilinguals: the use of two or more languages within the same sentence. The author concludes that there are universally present principles which govern the structural outlines of such sentences.

Clearly, Myers-Scotton's aim is to go beyond the mere listing of explanatory factors in codeswitching such as there are ... To my mind, Myers-Scotton's Markedness Model succeeds brilliantly in achieving this task ... Duelling Languages is such an extremely rich book that I cannot possibly do justice to it within the confines of the present review ... the book offers a readily accessible research programme to anyone wishing to enter the current debate. This alone, I presume, will do to entice the prospective reader. Myers-Scotton has most certainly done her homework - the amount of literature she has absorbed and presented in a most intelligent way is staggering.

`Clearly, Myers-Scotton's aim is to go beyond the mere listing of explanatory factors in codeswitching such as there are ... To my mind, Myers-Scotton's Markedness Model succeeds brilliantly in achieving this task ... Duelling Languages is such an extremely rich book that I cannot possibly do justice to it within the confines of the present review ... the book offers a readily accessible research programme to anyone wishing to enter the current debate. This alone, I presume, will do to entice the prospective reader. Myers-Scotton has most certainly done her homework - the amount of literature she has absorbed and presented in a most intelligent way is staggering.' Didier L. Goyvaerts, University of Antwerp, Journal of African Language and Linguistics `In recent years, there has been a flurry of publications on code-switching. Myers-Scotton's latest book Duelling Languages is a welcome addition to this group. Duelling Languages is the first book devoted entirely to developing a general theory of structural constraints on infrasential CS; as such, it is likely to stimulate much further thinking in the field.' Language in Society `a most welcome addition to the literature on structural constraints on code-switching, and will certainly be essential reading for anyone interested in the subject. The book provides a clear and carefully argued presentation of the MLF Model, set against a useful survey of previous literature.' Language, Vol 71 no 1 `excellent book...' Studies in Second Language Acquisition Vol 17:1 `the research presented in these two books exemplifies a thoroughness approaching the extraordinary ... So much energy! So much intelligence! Taken together, the books under review constitute a unique grammatical theory. Although the books are clearly intended for a general audience it cannot be denied that especially Africanists will get additional enjoyment from perusing Myers-Scotton's data base - the picture of Africa and the multilingual world that emerges from it is a vivid one.' Didier L. Goyvaerts, University of Antwerp and University of Brussels, JALL 16 (1995) `an extremely rich book that I cannot possibly do just to it within the confines of the present review ... As such, the book offers a readily accessible research program to anyone wishing to enter the current debate. This alone, I presume, will do to entice the prospective reader ... the amount of literature she has absorbed and presented in a most intelligent way is staggering.' Didier L. Goyvaerts, JALL 16 (1995) `clear and easy to read ... Myers-Scotton's work has developed into the dominant paradigm for present-day research in this field ... we wish to stress ... the importance of Myers-Scotton's work for the field ... It has linked psycholinguistic, sociolinguistic, and grammatical concerns and contains a number of valuable ideas that can lead to further hypotheses and a clearer view of how bilinguals function.' Pieter Muysken, Vincent de Rooij, University of Amsterdam, Linguistics 33 (1995