“了”是汉语中的一个常用虚词,由于其语义内容和句法行为的复杂性,长期受到汉语语言学界的重视。本文探索句末“了”(常称作“了2”)与焦点敏感副词(如“只”)同现的语义条件。焦点敏感副词和“了2”同现与“增量”和“余量”两个概念紧密联系。 “A ” is a commonly used function word in Chinese. Due to the complexity of its semantic content and syntactic behavior, it has long been valued by the Chinese linguistics community. This article explores the semantic conditions co-morphed with the focus-sensitive adverbs such as “only ” at the end of the sentence. Focus sensitive adverbs and “a 2 ” with the current and “incremental ” and “margin ” two concepts closely linked.