This article investigates the idea that the presence vs. absence of illocutionary potential in declarative clausal complements is syntactically reflected in the embedded clause. Specifically, we examine the joint claims (a) that clauses with illocutionary potential involve extended left-periphery encoding elements relevant to assertion, and (b) that clauses without illocutionary potential encode syntactic properties related to definiteness. To this end, we look at three phenomena commonly used to distinguish assertive and definite clauses (the licensing of Main Clause Phenomena, clausal anaphora, and extraction), asking whether their distribution across (factive and non-factive) embedding contexts tracks this pragmatic distinction. We find that among the phenomena investigated, only one (namely embedded V2, a type of Main Clause Phenomenon) fits the description above of being licensed only in contexts with illocutionary potential, which we understand as the potential to update the common ground with new information.