This paper discusses the semantics of two epistemic operators in Portuguese: the epistemic Future and modal verbs. The idea sustained in the literature for other languages that the epistemic Future has the same semantics as the modal verb (equivalent to) MUST does not account for the Portuguese data. The proposal is made that, though epistemic Future and epistemic modal verbs are devices to convey uncertainty, they operate on different grounds. Epistemic modal verbs are quantifiers over possible worlds, expressing a degree of epistemic commitment towards a proposition, while the epistemic Future is argued to be a mark signaling lack of evidence at the context of utterance. The other modal verbs of Portuguese, in their epistemic reading, are also considered, the proposal being made that Portuguese has also a modal verb that existentially quantifies over the set of Best worlds. This shows a very symmetric picture of Portuguese modal verbs: two of them select an ordered modal base and two others an unordered modal base; for each domain of quantification – the entire modal base or the set of Best Worlds (a subset of the modal base) – there will be an existential and a universal quantifier.

中文翻译：

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葡萄牙语中的认知未来和认知情态动词

本文讨论了葡萄牙语中两个认知运算符的语义：认知未来和情态动词。在其他语言的文献中，认知未来与情态动词（等同于）具有相同语义的观点必须不考虑葡萄牙语数据。提出的建议是，虽然认知未来和认知情态动词是传达不确定性的工具，但它们在不同的基础上运作。认知情态动词是可能世界上的量词，表达对命题的认知承诺程度，而认知未来被认为是在话语上下文中表明缺乏证据的标志。葡萄牙语的其他情态动词，在他们的认知阅读中，也被考虑在内，正在提出的建议是，葡萄牙语也有一个情态动词，可以对一组最佳世界进行存在量化。这显示了葡萄牙语情态动词的一个非常对称的画面：其中两个选择有序的情态基础，另外两个选择无序的情态基础；对于每个量化域——整个模态基础或一组最佳世界（模态基础的一个子集）——将有一个存在量词和一个全称量词。