Adjectives (e.g., hungry) are an important part of language, but have been little studied in individuals with impaired language. Adjectives are used in two different ways in English: attributively, to modify a noun (the hungry dog); or predicatively, after a verb (the dog is hungry). Attributive adjectives have a more complex grammatical structure than predicative adjectives, and may therefore be particularly prone to disruption in individuals with grammatical impairments. We investigated adjective production in three subtypes of primary progressive aphasia (PPA: agrammatic, semantic, logopenic), as well as in agrammatic stroke aphasia and a group of healthy control participants. Participants produced narratives based on picture books, and we coded every adjective they produced for its syntactic structure. Compared to healthy controls, the two agrammatic groups, but not the other two patient groups, produced significantly fewer attributive adjectives per sentence. All four patient groups were similar to controls for their rate of predicative adjective production. In addition, we found a significant correlation in the agrammatic PPA participants between their rate of producing attributive adjectives and impaired production of sentences with complex syntactic structure (subject cleft sentences like It was the boy that chased the girl); no such correlation was found for predicative adjectives. Irrespective of structure, we examined the lexical characteristics of the adjectives that were produced, including length, frequency, semantic diversity and neighborhood density. Overall, the lexical characteristics of the produced adjectives were largely consistent with the language profile of each group. In sum, the results suggest that attributive adjectives present a particular challenge for individuals with agrammatic language production, and add a new dimension to the description of agrammatism. Our results further suggest that attributive adjectives may be a fruitful target for improved treatment and recovery of agrammatic language.

形容词（例如，饥饿）是语言的重要组成部分，但在语言障碍个体中的研究却很少。英语中形容词有两种不同的用法：定语，修饰名词（饥饿的狗）；或表语，在动词之后（狗饿了）。定语形容词的语法结构比表语形容词更复杂，因此对于有语法障碍的人来说可能特别容易受到干扰。我们研究了原发性进行性失语症的三种亚型（PPA：语法障碍、语义障碍、语词减少）以及语法障碍中风失语症和一组健康对照参与者的形容词生成情况。参与者根据图画书制作叙述，我们根据句法结构对他们制作的每个形容词进行编码。与健康对照组相比，两个语法错误组（而不是其他两个患者组）每句话产生的定语形容词明显较少。所有四个患者组的预测形容词产生率均与对照组相似。此外，我们发现，语法错误的 PPA 参与者产生定语形容词的速度与复杂句法结构句子的产生受损之间存在显着相关性（主语裂句，如“It was the boy that eagers the girls”）；对于表语形容词没有发现这种相关性。无论结构如何，我们都检查了所产生的形容词的词汇特征，包括长度、频率、语义多样性和邻域密度。总体而言，所产生的形容词的词汇特征与每个组的语言概况基本一致。总之，结果表明定语形容词对具有语法错误的语言产生的个体提出了特殊的挑战，并为语法错误的描述增加了一个新的维度。我们的结果进一步表明，定语形容词可能是改善语法语言治疗和恢复的富有成效的目标。