Is denotes the passive past tense, with was ('was') denoting a more distant past - e.g. Hy is gister deur 'n by gesteek [3SG.M.NOM is yesterday by a bee stung] 'He was stung by a bee yesterday' vs. Hy was jare gelede deur 'n by gesteek [3SG.M.NOM was by a bee stung] 'He had been stung by a bee'. Because the adverbial clearly specifies the nature of the past reference, is is also possible in the latter case. See Donaldson (1993: 257–261) for discussion.