It is spoken in a relatively large area, extending from western Inner Carniola up to Trieste in Italy, also covering the upper Vipava Valley and the southern part of the Karst Plateau.

Geographically, the dialect is bounded by the Javornik Hills to the east and the national border to the southeast; it extends to the southwest to Gradišče pri Materiji, to the west to Slavnik and Kozina, in Italy to the coast, and to north to Predmeja.

[7] It has undergone four accent shifts: *ženȁ → *žèna, *məglȁ → *mə̀gla, *visȍk → vìsok, and *ropotȁt → *ròpotat.

Diphthongs mostly retained their form or have monophthongized in some parts, particularly near the Karst and Črni Vrh dialects, which come from different dialect bases and their diphthongs are therefore often different, which led to monphthongization on bordering microdialects on both sides.

Non-final *ō turned into uː, but remained a diphthong oːu before č, š, z, or s. *ī and *ā mostly remained unchanged, but *ū turned into yː, except in words introduced to the dialect later, where it is still uː.

The long infinitive was replaced by the short one, and the verb endings -ta and -te always have the -s- infix (pˈriːdesta, ˈviːdiste).

In most rural areas, especially in the Vipava Valley and on the Karst Plateau, the dialect predominates over standard Slovene (or its regional variety).

In the towns, where commuting to the capital, Ljubljana, is more common (Postojna), the dialect is being slowly replaced by a regional version of standard Slovene.