Keenan Stavi 1986, Keenan 1996) considers that they result from the application of a discontinous determiner to a common noun.
examples are given in (29) and (30): (29a) every student will swim unless it is raining (29b) every student will swim except if it is raining (30a) Leo will go to the party unless he is tired (30b) Leo will go to the party except if he is tired Now it is clear that given the above equivalent sentences of the first type can be directly analysed in the same way as the sentences in which eXCL phrases occur and which are analysed in the preceeding section.