Why are French and Romanian considered peripheral Romance languages?

In the study of Romance languages, the terms "central" and "peripheral" are used to describe the degree of mutual intelligibility and linguistic similarity between languages. While standard Italian is often considered a "central" language due to its high degree of similarity and intelligibility to other Romance speakers, French and Romanian are classified as "peripheral" because they lack this same level of similarity, requiring more effort for other Romance speakers to understand them.12

The reasons for this peripheral status differ for each language:

• French: It has diverged significantly from the rest of the family, particularly through radical phonetic changes and a shift in grammatical typology that places greater reliance on word order and intonation rather than morphological forms.32
• Romanian: While it remains closest to Latin in certain grammatical types, its vocabulary has been heavily influenced by Slavic, Turkish, and other neighboring languages due to its geographic isolation from the rest of the Romance-speaking world.24

These classifications are based on nonhistorical measures of differentiation rather than traditional family tree models.1