Dialectology

Dialectology (from Ancient Greek διάλεκτος, dialektos 'talk, dialect' and -λογία, -logia) is the scientific study of dialects and other forms of language variation, especially variation associated with geographic region. Dialectologists investigate differences in pronunciation, grammar, and vocabulary, and how such differences pattern across communities and change over time.

The field developed in the 19th century alongside historical linguistics and became closely associated with large-scale dialect surveys and the production of dialect maps and linguistic atlases. Such work typically relies on systematic data collection (for example, questionnaires, interviews, and recordings) and represents the geographic distribution of linguistic features using concepts such as isoglosses and dialect boundaries.

From the mid-20th century onward, dialectology has increasingly overlapped with sociolinguistics and variationist approaches, extending its focus from primarily rural, long-established speakers to include urban varieties, social differentiation, and the effects of migration and language contact. Topics commonly discussed in dialectological research include mutual intelligibility and the language–dialect distinction, diglossia, dialect continua, and the relationship between regional varieties and standard forms in pluricentric languages.