Every day we negotiate our social relations. This may involve small, seemingly inconsequential chats with friends, families, and colleagues that perform our relationships. Or they may involve large, communal events that bring us together or tear us apart. In all cases, we negotiate these social relations through the language, paralanguage, and related systems of meaning that we use. This book introduces a new model for analysing how people negotiate social relations through the framework of Systemic Functional Linguistics (SFL). It focuses on SFL's conception of social context and in particular on the interpersonal component of context known as tenor. Drawing on decades of SFL research, tenor is reworked as a resource for meaning – with the aim of describing in some detail how we go about building and maintaining sociality.The book begins by considering how language varies in relation to social context and the different perspectives we can take to explore this variation. It then introduces our model of tenor as a resource for negotiating social relations. The model comprises three main systems. Positioning considers how people put forward meanings, react to them, and position each other when we talk. Orienting looks at the nature of the meanings we negotiate, attending to the vast background of shared values that underpin our talk, help us build communities, and hold them together. Tuning deals with how we raise or lower the stakes of what is being said, how we broaden or narrow the scope of what it applies to, and how we vary the spirit in which the meanings are being put forward. Taken together, these systems provide us with resources for enacting social relations as we align and disalign with people and communities of various kinds. Examples focus in particular on a range of meanings associated with motherhood, including language and paralanguage (both gesture and emoji) in spoken, written, and social media texts.