This text is designed as an introductory resource for those who wish to carry out or study research in children's language development, teaching English as a second language, children's literature, causal conversation, social class and language variation and other applied language research fields. The contributors are researchers in the field and introduce approaches to investigating such areas using systemic functional linguistics (SFL). A key purpose of the text is to facilitate the further engagement of language researchers with SFL perspectives, encouraging more collaborative transdisciplinary work across different fields of study and theoretical approaches in projects of mutual concern. The first two chapters outline the key aspects of SFL's relationship within language and social context and the inter-related text structures and grammatical systems. This provides background for those new to SFL to make productive, critical use of the research reviewed, studies described and advice on project design provided in the following chapters. The book is intended as an introductory resource and, as such, particular attention has been paid to provision of clear references to more elaborated accounts of important issues discussed.