Carers recognize that the linguistic problems associated with Alzheimer's disease (AD) can be detrimental to effective communication, but they are often not sure what they can do to help. This article examines the use of formulaic language in AD, including routines, repetitions, and fillers, through the lens of a model of how cognitive and social priorities shape language learning and use. The model sheds light on the ways in which formulaic language can limit effective communication, but also shows how it can be used to support the declining command of novel language. Carers' tendency to adopt formulaic language in their own interaction is also examined. An agenda for future research is offered to further test the validity of these observations and to explore ways of using formulaic language constructively to support improved communication between carers and AD sufferers. (Contains 1 note.)