Many languages have past-and-counterfactuality markers such as English simple past. There have been various attempts to find a common definition for both uses, but I will argue in this paper that they all have problems with (a) ruling out unacceptable interpretations, or (b) accounting for the contrary-to-fact implicature of counterfactual conditionals, or (c) predicting the observed cross-linguistic variation, or a combination thereof. By combining insights from two basic lines of reasoning, I will propose a simple and transparent approach that solves all the observed problems and offers a new understanding of the concept of counterfactuality.

中文翻译：

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反事实和过去

许多语言都有过去和反事实标记，例如英语简单过去时。已经有各种尝试为这两种用途找到一个共同的定义，但我将在本文中争辩说，它们都存在以下问题：（a）排除不可接受的解释，或（b）解释反事实与事实相反的含义条件，或 (c) 预测观察到的跨语言变化，或其组合。通过结合来自两个基本推理思路的见解，我将提出一种简单而透明的方法来解决所有观察到的问题，并提供对反事实概念的新理解。