In this paper, we focus on the question of what accounts for the cross-linguistic differences we see in how 'standard' aspect (and tense) is realized in Counterfactual (CF) constructions. We propose that languages attempt to maximize the exponents of tense/aspect that correspond to the interpretation of the sentence, while still always realizing the tense/aspect morphology required by the CF construction. We explore the morphological composition of tense and aspect in CF constructions in two unrelated languages, Palestinian Arabic and Zulu, to illustrate this principle. We show that in PA, imperfective is not required in CFs and aspect morphology always receives its standard aspectual interpretation. In Zulu, by contrast, imperfective morphology is required in all CFs and does not always receive its standard aspectual interpretation in these constructions. We argue that these differences are determined by two factors: (1) the specific feature bundling of tense and aspect morphology in the language and (2) the availability of strategies that allow tense/aspect morphemes to be 'stacked' on a single main verb in CFs. Despite such differences, we identify two points of commonality that drive morphological marking in CFs in the two languages: (1) both languages use past tense to mark CFs and (2) both languages attempt to maximize the morphological exponents of 'real' tense and aspect. The different ways in which each language implements these requirements are independently predictable from the specifics of their individual morphosyntactic properties.