The occurrence of any event represents some sort of ‘change’ in the state of affairs obtaining at a particular time or location. Languages typically encode this change of ‘state of affairs’ in the tense/aspectual system. Consider the isiXhosa examples in (1) and (2):

(1) UAyanda uzikamile iinwele zakhe
U-Ayanda u-zi-kam-ile ii-nwele z-akhe
1-Ayanda 1SM-10OM-comb-PST 10-hair 10-3SG.POSS
‘Ayanda combed her hair”

(2) UAyanda ebezikamile iinwele zakhe
U-Ayanda ebe-zi-kam-ile ii-nwele z-akhe
1-Ayanda 3SG.PST-10OM-comb-PST 10-hair 10-3SG.POSS
‘Ayanda combed her hair”

The most obvious difference between the two sentences is that (1) uses what is called a simple tense form whereas (2) uses a compound tense form. A more important difference lies in meanings associated with each sentence: (1) implies that at utterance time Ayanda’s hair is (likely to be) kempt whereas (2) implies that it isn’t. In this presentation I argue that events have the capacity to ‘cast shadows’ spanning the period in which the effects of an event persist. This ‘shadow’ may or may not include utterance time (UT). I demonstrate that in isiXhosa and related languages the inclusion or exclusion of UT in the ‘shadow’ the event’s post-time engenders different morpho-phonological marking on the verb. I also show that the exclusion of UT in the ‘shadow’ is restricted by the semantics of the verb.