This chapter explores the connection between past tense and modality in English and French. After arguing for a temporal definition of past tenses, I reinterpret the classical opposition between temporal uses and modal uses in terms of the speakers's referential or subjective intentionality. I further distinguish between the epistemic uses – which express the speaker's assessment of the probability of the denoted situation – and the illocutory uses – which express the speaker's degree of commitment in her speech act. I finally suggest an analysis of two epistemic uses of the English simple past and the French imperfect, namely their conditional use and optative use, thanks to the notion of dialogism, which refers to the heterogeneity of the enunciative sources of a given utterance.