Abstract
This paper is concerned with the grammatical construction exemplified by the sentence used as the subtitle, Just because because-clauses can substitute for that-clauses does not mean that this is always possible, where the because-clause is used as a nominal clause. It is shown that, syntactically, this construction derives from the blending of a construction with a that-clause as subject and one with an adverbial because-clause, and that, semantically, the construction is used to deny the inferential process of drawing a certain conclusion from a certain factual premise and to express some doubt about the validity of the conclusion as well. Through a close investigation of this particular construction and some related matters, it is suggested that the syntax of a grammatical construction is constrained in such a way that the construction is used for exactly the purpose it is expected to serve.
