This article focuses on two fragmentary constructions in English: why-fragments (WFs), such as Why (deal with) why-fragments?, and Mad Magazine sentences (MMs), such as (Me) paint the house purple? While both types can be equivalent in meaning to their corresponding fully fledged interrogative sentences, they can also be used to convey a specific nuance of scepticism regarding a particular proposition. To explore the specific nuance enriching the canonical interpretation (i.e. equivalent to that of the corresponding complete questions) of WFs and MMs, and their potential constructionalisation in contemporary English, two corpus-based studies were conducted using data from the BNC1994 DS, Spoken BNC2014 and COCA. The results show that MMs seem to be fully constructionalised, while the significant trends attested for WFs indicate an ongoing process of constructionalisation, at least in contemporary British English. The evidence also shows that both may be classed as examples of an umbrella ‘Sceptical Small’ construction.