The past 20 years have seen an unprecedented upsurge of interest in multilingualism. A major reason for this is no doubt the acknowledgement by a growing number of researchers that the use of more than two languages is far more common than was previously thought. The exact number of multilinguals around the world is unknown. However, we know that there are approximately 6,000 languages at this time being spoken in the world (Grimes, 1992). Since there are only 203 countries in the world, simple mathematics tells us that many countries must, in one way or another, be bi- or multilingual (Dewaele, Housen & Wei, 2003). An investigation of the phenomenon of multilingualism and multiple language acquisition, therefore, has not only a huge theoretical significance but also has great practical importance.
Thus, in this context, I suggest that it would be both interesting and useful to present a volume focusing on the concept of multilingualism containing a number of theoretical papers and experimental studies which include data from various parts of the globe. This volume also focuses on some major aspects of trilingualism from diverse theoretical and methodological points of view which have been written by internationally renowned scholars.