Final answer:
Lexical categories are classes of words with similar grammatical properties, fundamental in organizing a language's lexicon and crucial for sentence structure and meaning. Linguistic universals and linguistic relativity both influence how categories are formed across different languages and cultures.
Step-by-step explanation:
The term lexical categories refers to the classes of words that share a set of grammatical properties across languages. These categories are fundamental to understanding language structure and use because they help organize the lexicon, which is the vocabulary of a language. In English and many other languages, lexical categories include nouns, verbs, adjectives, and adverbs, among others. Each category plays a specific role in sentence structure and meaning.
Categorization is a cognitive process that is essential to human language. It involves organizing experiences and perceptions into categories, which are an intrinsic part of language development and communication. While there are some similarities across languages, known as linguistic universals, the way in which cultural experiences shape language can lead to great diversity, a concept known as linguistic relativity. Both linguistic relativism and universalism play a critical role in the formation of lexical categories and the evolution of language.