What does "vernacular" mean?

The term "vernacular" refers to the everyday language spoken by the people in a particular region or community. It encompasses the common speech patterns, idioms, and dialects that are used among the general population, distinguishing it from formal or literary language. This concept highlights how language can differ significantly depending on social and regional contexts.

The other options do not align with the definition of "vernacular." While the formal language used in literature represents the structured and authored aspect of language, the vernacular is inherent to casual, spoken dialogue. Similarly, technical or specialized language is associated with specific fields or professions, which is quite different from the informal, accessible nature of vernacular speech. A poetic form of expression, on the other hand, suggests a stylized use of language that also contrasts with the straightforward and everyday qualities of vernacular language. Thus, the best choice that captures the essence of "vernacular" is indeed the everyday speech of the people.