The Norwegian dialects are commonly divided into 4 main groups, Northern Norwegian (nordnorsk), Central Norwegian (trøndersk), Western Norwegian (vestlandsk), and Eastern Norwegian (østnorsk). Sometimes Midland Norwegian (innlandsmål) and/or South Norwegian (sørlandsk) are considered fifth or sixth groups.The dialects are generally mutually intelligible, but differ significantly with regards to accent, grammar, syntax, and vocabulary.