This paper analyzes utterances of the type Le facteur qui passe ! and other related constructions from the point of view of expression of emotion, and in terms of dethematization (and rhematization). Our basic hypothesis is that the emotional value of an utterance is not always determined by lexical elements contained in it, but can be assured by the construction itself. Thus, we propose that (i) the utterances in question are dethematized (or themeless) utterances, that (ii) the systematic presence of the exclamation mark, which by definition represents an emotional value, is due to the fact that the sequence ‘NP qui VP’ is a nominal form and as such an incomplete sentence, as is the case with one-word (or one-phrase) sentences which need an exclamation mark to attain the status of utterances (aïe !, à la bonne heure !, au secours !), and that (iii) these two particularities as utterances are explained through the function(s) of the relative pronoun qui as marker of dethematization and of nominalization.