The paper addresses the problem which consists in that the semantic content of an utterance is often much richer than the content fixed by the semantic conventions and compositionality. The semantic content of an utterance is, therefore, supposed to involve so-called unarticulated constituents, over and above those articulated at the linguistic level. It is often claimed that this problem undermines traditional conceptions of semantics. The paper shows that every unarticulated constituent has to be determined at the syntactic level. Consequently, there are no unarticulated constituents tout courts. This claim is resulting from a careful specification of the notions used to show that there are unarticulated constituents (the notion of sentence, the notion of expression, the notion of using as opposed to that of saying, etc.). Given these specifications, it is possible to develop a theory of syntactic ellipsis as a viable solution to the above mentioned problem.