Scientific literacy is approached on the premise that language is key to understand the nature of both learning and participation, in scientists’ practices as well as in liberal education for citizenship. Some of the questions that are addressed in the book are: • What does it take to be able to participate in different arenas in society involving science? • How does everyday language relate to scientific language? • How can students’ texts be analyzed to gain insights into their learning? • How can images be analyzed alongside verbal language? This book offers a thorough introduction to key ideas in M. A. K. Halliday’s systemic functional grammar through examples and practical analysis. Detailed analysis is offered of science textbooks and curriculum documents, classroom talk, experimental work, and students’ discussions of complex environmental issues. Further, an analytical model guiding the design and analysis of science learning discourses is introduced. The book starts with introducing excerpts from whole-class discussions, group work, experimental reports and textbooks as text-in-context. From this starting point, key aspects of language are carefully explained. The role of grammatical metaphor in the development of science knowledge is an important topic throughout the book. Tools for analyzing multimodal representations, intertextuality and multiple voices are also among the topics covered for understanding and analyzing school science discourses.