Around the age of 4 to 5 years old, typically developing children begin to successfully reason about what others know or believe and draw inferences regarding how these mental states will affect how a person behaves. This maturational milestone of metarepresentational abilities has been identified for both false-belief (FB) reasoning tasks as well as intensionality tasks. The aim of this study is to assess relations between these two metarepresentational capacities (FB reasoning and intensionality) and importantly their relation to maturation of embedded clauses among children with ASC and children with typical development. An important motivator for this study is evidence that there is a strong link among both these populations between performance on FB reasoning (Sally-Anne tasks) and linguistic maturation, in particular clausal embedding. This study aims to fine-grain the nature of the relation between complex syntax and metarepresentation by systematically assessing various clausal embedding types and expanding metarepresentation assessment to include intensionality tasks.