The past marker is a phonologically fused second order prefix; the only first order prefix is the perfective marker ka- (and this intervenes between the tense-marker and the verb).
The verb teem 'be' has the suppletive past form tiɲa and the verb andaa 'go' has an optional suppletive past stem: jaa-foy alongside regular jaa-andaa. Auxiliaries carry a clause's tense-marking. Tense and aspect generally are marked by separate morphemes, but when teem/ tiɲa is used as the perfect marker, tense and aspect are fused into a single form: e.g. uŋ gɔɔta jeentis-pa mee falaa tiña [one few people-DAT FOC tell be:PST] 'He had only invited a few people.'
Source: Smith 1974-5: 5105
Source: Smith 1974-5: 5092-4