Research on the (in)definiteness of bare nouns has developed various proposals regarding which type-shifters exist in human language and which principles are needed to govern their distribution (Carlson 1977; Partee 1987; Chierchia 1998; Dayal 2004; i.a.). At the same time, literature on headless relative clauses (HRCs), primarily focusing on free relatives (FRs) in Indo-European languages, has also developed type-shifting principles (Jacobson 1995; Caponigro 2003, 2004). The type-shifting principles from the FR literature, however, are fundamentally different than those found in proposals for bare nouns. Here, we present case studies from two Mayan languages which diverge from one another in the behavior of bare nouns, and which possess several different kinds of headless relative clauses. We show that “super-free relative clauses” (Caponigro et al. 2021; Caponigro 2022), which lack a wh-word, pattern in ways parallel to bare nouns in the respective languages. We also demonstrate that HRCs headed by a wh-word—i.e., FRs—diverge from bare nouns; they pattern similarly to one another across the languages under investigation, and in ways similar to what has been reported for FRs crosslinguistically. We provide evidence that there is a dedicated FR type-shifter (FR-ι) used as a post-syntactic mechanism to repair a type-mismatch at the CP level, building on work by Caponigro (2004). Our novel contribution is that this type-shifter is available regardless of the presence or absence of other type-shifters in a language. This paper adds new data to our understanding of the range and applicability of different definiteness-related type-shifters as well as captures certain typological tendencies regarding HRCs.

关于裸名词的（不）确定性的研究提出了各种建议，涉及人类语言中存在哪些类型转换以及需要哪些原则来管理它们的分布（Carlson 1977；Partee 1987；Chierchia 1998；Dayal 2004；ia）。与此同时，关于无头关系从句（HRC）的文献，主要关注印欧语言中的自由关系（FR），也发展了类型转换原则（Jacobson 1995；Caponigro 2003，2004）。然而，FR 文献中的类型转换原则与裸名词提案中的类型转换原则根本不同。在这里，我们提出了两种玛雅语言的案例研究，它们在裸名词的行为上彼此不同，并且拥有几种不同类型的无头关系从句。我们展示了“超级自由关系从句”（Caponigro et al. 2021；Caponigro 2022），它缺乏 wh 词，其模式与各自语言中的裸名词平行。我们还证明以 wh 词（即 FR）开头的 HRC 与裸名词不同；它们在所调查的语言中彼此模式相似，并且与跨语言的 FR 报告的方式相似。我们提供的证据表明，在 Caponigro (2004) 的工作基础上，存在一个专用的 FR 类型转换器 (FR- ι )，用作句法后机制来修复 CP 级别的类型不匹配。我们的新颖贡献是，无论语言中是否存在其他类型转换器，该类型转换器都可用。本文为我们对不同确定性相关类型转换的范围和适用性的理解添加了新数据，并捕获了有关 HRC 的某些类型学趋势。