Norwegian dialects (dialekter/ar) 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.