Which mechanism describes how a linguistic feature spreads from one speech community to another, often influenced by prestige?

• A. Standardization
• B. Isolation
• C. Fragmentation
• D. Diffusion

Answer: (D)

Diffusion describes how a linguistic feature moves from one speech community to another through contact, exchange, and social interaction. When a feature is linked to prestige, speakers adopt it to align themselves with a socially desirable group, amplifying its spread across communities via conversation, media, migration, and online networks.

Standardization, by contrast, concentrates norms within a single community or institution, not primarily in cross-community spread. Isolation would block contact and thus prevent diffusion. Fragmentation involves the breaking apart of dialects into smaller varieties, not the outward spread of a feature between communities.

So the mechanism best describing spread between speech communities, especially under prestige influence, is diffusion.