This mixed methods multiple case study examines formulaic language in the speech of four children with autism spectrum disorder (ASD). Play sessions were recorded to collect speech samples. Parents of participants acted as informants during the recording sessions and completed questionnaires. Three analyses were carried out: a qualitative analysis of situational factors that potentially impacted the prevalence of formulaic language, a quantitative analysis of the prevalence of formulaic language in speech samples using a classification system developed for the study, and a qualitative
functional analysis of 36 formulaic sequences. Various situational factors increased or decreased formulaic language use, though all four participants used formulas. Formulas corresponded to several categories and varied in conventionality, whether in form or function. Nonetheless, the qualitative analysis indicated that formulas had several functional uses in the interactions of participants. These findings have implications for future research and language assessment and intervention in ASD.