Approximately what is the purpose of a lexicon in language?

A lexicon serves the vital function of listing words along with their meanings within a particular language. It can be thought of as the vocabulary inventory of a language, providing definitions, usages, and sometimes additional information like pronunciations or examples. This resource is essential for understanding and using language effectively, as it contains the building blocks of communication—words.

In contrast, defining grammatical rules pertains to understanding how words fit together in sentences, which goes beyond merely knowing word meanings. Analyzing sentence structure deals with the arrangement and relationship of words within sentences, focusing on grammar rather than word definitions. Studying phonemic differences involves examining the sounds in a language and how they contribute to meaning, which also requires a distinct focus separate from the lexicon's role. Thus, the primary purpose of a lexicon is indeed to list words and provide their meanings, making option B the most accurate choice.