This presentation addresses the modal (i.e. indeterminate) nature of if-conditionals. If-conditionals are seen as bipartite constructions (Fillmore 1986: 196, 1998: 36) with a significantly higher than average modal load. The discussion will also draw on the notion of “mental spaces” (Fauconnier 1994) as adapted for conditionals by Dancygier & Sweetser (2005). The high modal load of if-conditionals is made all the more intriguing if we consider that they are already within the scope of the modal marker 'if'. However, the high modal load cannot not, in itself, define their modal nature. Two questions are pertinent to that nature: Can they be seen as being modalised? Can they be seen as being modal themselves? It will be shown that a remarkable characteristic of if-conditionals (and, it would seem, conditionals in general) is that they are modally dense constructions, without being either externally modalised or modal themselves. Moreover, the case will be made that if-conditional constructions are internally modalised – or self-modalised. Seen as such, if-conditional constructions can usefully be treated as the language equivalent of quantum bits, and this can be exemplified through a compatible adaptation of the box in Schrödingers’ famous thought experiment (1935, English translation by Trimmer 1980). This conception can show how the fundamental nature of if-conditionals gives rise to their different types and functions in English.