This paper shows that some individuals with Down syndrome are capable of producing, imitating (repeating) and comprehending passive sentences, even though group studies indicate that this is not the norm. Experimental tests of elicited production, repetition and comprehension of passive and active sentences applied in ten adolescents with Down syndrome, speakers of Portuguese, showed that out of the ten adolescents, one, Fa, is able to produce, imitate and comprehend passive sentences. It is hypothesised that, when there is no comprehension, or when the comprehension of reversible passives is unstable, the passive is understood as active, because the first noun of the passive sentence is interpreted as agent/causer of the action/non-action. This hypothesis is strong inasmuch as it assumes that both active and passive have very similar initial derivations. There is not, however, strong evidence that the nine adolescents interpret the passive as active. But if it is assumed that their chance results in comprehension of the passive is due to the fact that they are beginning to understand it, then it could be said that, for around 50% of the time, the adolescents with Down syndrome interpret the passive as active. Fa, on the other hand, does not interpret the passive as active, as she produces, imitates and comprehends the passive structure very well. (Contains 1 figure, 6 tables and 18 footnotes.)