I refer to the sentences that are the subject of this paper as Thing sentences (TSs), illustrated by The thing is that it’s not my phone. These are copular specificational sentences with a definite singular subject and a finite complement clause. Prior research claimed that TSs focus attention on their complement clauses, are pragmatic or discourse markers, indicate a shift in subtopic or topic, communicate that the proposition represented by the complement clause is in “disconformity” with, or problematic in, its context, and that it represents a cause, reason, justification, or grounds for other propositions; these interpretations are claimed to be conventionally associated with the construction. I show that these earlier works are descriptively inaccurate and explanatorily incomplete. While the cause, reason, justification, and grounds interpretations have not been explained, some authors have claimed that the problem interpretation is due to the semantic poverty of thing. I demonstrate that the construction presents the complement proposition as both focused and presupposed and consequently as partially discontinuous with the discourse topic as it has developed up to the point at which the TS is uttered, thereby effecting a shift in the development of the current topic, though never a shift to an unrelated topic. I argue against analyzing TSs as discourse or pragmatic markers and I demonstrate that TSs need not communicate that their complements are problematic, that the range of other interpretations is greater than hitherto proposed, that these are due to the operation of general interpretive schemata, and therefore are not conventionally associated with the construction. I show that the presuppositional effects are due to the minimal semantic specification of thing and the fact that it is definite, and that the focusing effects are due to the predicate position of the clause and to the specificationality of the construction which makes the clause an argument of the subject and thus a marked focus. This analysis of Thing sentences demonstrates that speakers are attuned to the expectations of their audiences and exploit the lexical and syntactic resources of the language to create expression types to manage such things as topical development, and in the case of Thing sentences to signal an unexpected development of the current topic, leading to a change in its trajectory. The analysis shows that at this point in its history, TS interpretations are due to its linguistic features interacting in context with general pragmatic principles.