The linguistic distinction between function words (functors) (e.g., the, he, that, on…), signaling grammatical structure, and content words (e.g., house, blue, carry…), carrying meaning, is universal across the languages of the world. These two lexical categories also differ in their phonological makeup (functors being shorter and more minimal) and frequency of occurrence (individual functors being much more frequent than most content words). The frequency-based discrimination of the two categories could constitute a powerful mechanism for infants to acquire the basic building blocks of language. As functors constitute closed classes and content words come in open classes, we examined whether 8-month-old monolingual infants relied on word frequency to categorize and track functors and content words. In six artificial grammar-learning experiments, we have found that infants process frequent words as belonging to closed classes, and infrequent words as belonging to open classes, and they map the relative order of these categories following the basic word order of their native language. These findings provide the earliest evidence that infants use word frequency as a cue to lexical categories and combine them to build rudimentary representations of grammar.

中文翻译：

---

词频是8个月大婴儿的词汇类别的提示。

功能词（functors）（例如，……，……，……），表示语法结构和内容词（例如，house，blue，carry…）之间的语言区别在整个语言中是通用的世界。这两个词法类别在语音构成（短音短而更小）和出现频率（单个函子比大多数内容词更频繁）上也有所不同。这两类基于频率的歧视可能构成婴儿获得语言基础的强大机制。由于函子构成封闭类，而内容词属于公开课，因此，我们检查了8个月大的单语婴儿是否依赖词频来对函子和内容词进行分类和跟踪。在六个人工语法学习实验中，我们发现婴儿将频繁使用的单词归为封闭类，而将很少使用的单词归为开放类，并且他们按照其母语的基本单词顺序来映射这些类别的相对顺序。这些发现提供了最早的证据，即婴儿使用词频作为词汇类别的线索，并将它们结合起来以构成语法的基本表示。