This is an introduction to the Special Issue Lexical constraints in grammar: Minority verb classes and restricted alternations. In many languages, grammatical relations are subject to lexical constraints. These constraints can be manifested in different morphosyntactic domains, for instance, through deviation from canonical case frames or different argument indexation patterns. Other constructions that have been studied through this lens are voice and valency constructions and some clause-combining constructions. The types of oppositions established by lexical constraints vary: some absolute restrictions entail the obligatory presence or absence of a grammatical marker, while others entail the ability of a lexical item to alternate. In the latter instance, differences in the statistical preferences for one construction over another may be observed. In some cases, verb classes can be easily identified based on a common semantic feature; however, various other factors can also lead to the formation of minority verb classes and restrictions on alternations. This article introduces a collection of four articles investigating lexical constraints in a variety of morphosyntactic domains, adopting different perspectives and methodologies. It sets out a framework for considering different opposition types formed by the differing behaviour of different verb classes and outlines a number of different factors that motivate the formation of verb classes. This introductory article shows that lexical constraints provide fertile ground for typologists adopting a token-based approach seeking to compare languages at ever-greater levels of specification.

中文翻译：

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语法中的词汇约束简介：少数动词类别和受限交替

这是对语法中的特殊问题词汇约束的介绍：少数动词类别和限制性交替。在许多语言中，语法关系受到词汇的限制。这些约束可以在不同的形态句法域中体现出来，例如，通过偏离规范案例框架或不同的参数索引模式。通过这个镜头研究的其他结构是语音和配价结构以及一些从句组合结构。由词汇约束建立的对立类型各不相同：一些绝对限制需要语法标记的强制存在或不存在，而另一些则需要词汇项交替的能力。在后一种情况下，可以观察到一种结构相对于另一种结构的统计偏好的差异。在某些情况下，可以根据共同的语义特征轻松识别动词类别；然而，各种其他因素也可能导致少数动词类的形成和对交替的限制。本文介绍了四篇文章的集合，采用不同的视角和方法，研究各种形态句法领域的词汇约束。它提出了一个框架，用于考虑由不同动词类别的不同行为形成的不同对立类型，并概述了激发动词类别形成的许多不同因素。这篇介绍性文章表明，词汇约束为类型学家采用基于标记的方法寻求在更高规范水平上比较语言提供了肥沃的土壤。