The main objective of this following paper is to present the Portuguese future tenses together with their Polish equivalents. On the basis of the examples taken from Vergilio Ferreira’s novel Para Sempre, we are trying to describe the main functions of the future tenses. In Portuguese, the future can be expressed by different forms of the verb: simple and complex ones. In our work, we describe the use of imperfeito tense, the periphrastic verbal structures and the future simple tense. Not only do we analyze the variety of different grammatical tenses but we also explain the intricacies of aspect and modality (expressing the uncertainty, wish, probability or obligation). It is important to notice that in Polish, some future forms in Portuguese are replaced by the past forms or by the subjunctive.