Why is the boundary between a language and a dialect difficult to define for Romance varieties?

Defining the boundary between a language and a dialect within the Romance family is inherently difficult because the distinction is often based on sociopolitical factors rather than purely linguistic ones.12

Several key factors contribute to this ambiguity:

• Mutual Intelligibility: While dialects of the same language are typically considered mutually intelligible, this criterion is relative. Speakers of closely related Romance languages can often communicate to a degree, making it difficult to establish a firm threshold for separation.12
• Political and Social Status: The most common definition of a "language" is political—a variety accepted as a standard by a nation or people. Consequently, varieties that were once considered dialects of a national language (such as Galician or Piedmontese) may be reclassified as distinct languages as they gain political or cultural significance.2
• Geographic Continuity: In many regions, such as Italy, neighboring dialects form a continuum where differences become more marked only with geographic distance, making it arbitrary to draw a line between a "dialect" and a "language".12
• Historical Classification: Methods of subgrouping, such as family tree classification, often yield different results depending on which linguistic features (e.g., stressed vowels vs. vocabulary) are prioritized, complicating the status of varieties like Franco-Provençal or Rhaetian dialects.32