Norwegian dialects (dialekter) are commonly divided into four main groups, 'Northern Norwegian' (nordnorsk), 'Central Norwegian' (trøndersk), 'Western Norwegian' (vestlandsk), and 'Eastern Norwegian' (østnorsk). Sometimes 'Midland Norwegian' (midlandsmål) and/or 'South Norwegian' (sørlandsk) are considered fifth or sixth groups.
The dialects are generally mutually intelligible, but differ significantly with regard to accent, grammar, syntax, and vocabulary. If not accustomed to a particular dialect, even a native Norwegian speaker may have difficulty understanding it. Dialects can be as local as farm clusters, but many linguists note an ongoing regionalization, diminishing or even elimination of local variations.
Normalized speech, following the written languages Bokmål and Nynorsk or the more conservative Riksmål and Høgnorsk, is not in common use, except in parts of Finnmark (where the original Sami population learned Norwegian as a second language), in much of Østlandet, certain social groups in major urban areas elsewhere (e.g. Trondheim), in national broadcasting, and in courts and official decrees.
West and South Norwegian
South Norwegian (Aust-Agder, most of Vest-Agder and Fyresdal, Nissedal, Drangedal and Kragerø in Telemark)
South-West Norwegian (inner parts of Sogn og Fjordane, Hordaland (except the city of Bergen), Rogaland, and western parts of Vest-Agder)
Bergen Norwegian or Bergensk (Bergen)
North-West Norwegian (Romsdal, Sunnmøre, Nordfjord, Sunnfjord and outer parts of Sogn)
North Norwegian
Helgeland Norwegian (Nordland county south of Saltfjellet, except for Bindal)
Nordland Norwegian (Nordland county north of Saltfjellet)
Troms Norwegian (Troms county, except for Bardu and Målselv)
Finnmark Norwegian Finnmark county, except for Northern Kautokeino, Northern Karasjok, Tana and Nesseby.