This chapter has three major purposes. First, it introduces the material which will count as CS examples, while also offering something of the spirit of the conversations containing them. Second, it details the data set and the sociolinguistic background for the conversations from which the majority of CS examples will come. This is the Nairobi Corpus. Third, it indicates that the goal of this volume will be to propose a structurally based model to account for where in a sentence switches from one language to the other may occur.
It is worth emphasizing that, while the data cited largely represent Swahili/English CS in Nairobi, this book is not intended primarily as a descriptive study of that data base. The main purpose in including these data is to provide a quantitative basis for testing the MLF model. That is, all instances of CS within the forty conversations constituting the Nairobi corpus are considered in the analysis. The very few instances which are exceptions to the claims of the MLF model are discussed along with the majority of examples, which support the model.
In addition, all relevant examples available in the general CS literature are also considered. Again, both potential counter-examples and examples supporting the MLF model are discussed.