In mediaeval logic a common term is often said to supposit simply, if it supposits for a concept and not for the elements of its extension. Due consideration of the logical texts of the 13th century, however, gives rise to the assumption, that a) the common aspect of the several uses of a term which are referred to as simple suppositions is not so easy to be found and that b) for some authors simple supposition was an extensively used tool for the logical analysis of sentences. In my paper I will enlarge on this second aspect with particular reference to the syncategoremata of William of Sherwood. My study leads to the conclusion that simple supposition in the 13th century is sometimes used to analyse scope ambiguities between the existential quantor and another operator. This is due to the fact that mediaeval logicians did not conceive of anything equalling an existential quantor.