Somali dialects are divided into three main groups: Northern, Benaadir and Maay. Northern Somali (or Northern-Central Somali) forms the basis for Standard Somali. Benaadir (also known as Coastal Somali) is spoken on the Benadir coast from Adale to south of Merca, including Mogadishu, as well as in the immediate hinterland. The coastal dialects have additional phonemes which do not exist in Standard Somali. Maay is principally spoken by the Digil and Mirifle (Rahanweyn) clans in the southern areas of Somalia.