The goal of this contribution is to deepen our knowledge of French cleft sentences through the study of a special category of
clefts called adverbial clefts. The issues that we will address concern their form, discourse frequency and
boundaries with resembling structures. In order to shed light on these issues, we start by defining the concept of
adverbial from a morphosyntactic and functional point of view. We then present a corpus-based description of
the categories of adverbials that can be cleaved. Finally, we propose a general semantic principle capable of describing and
explaining, in a coherent and unitary way, both the data obtained in our empirical study and found in the form of constructed
examples in the existing literature. In addition to explaining why certain adverbials can be cleaved while others cannot, this
principle also allows for a distinction to be made between two syntactic realizations of the structure ‘c’est Adv que p’, as well
as for a solution to the controversial issue of the status of domain adverbials.