There are four main dialects of Maldivian. (Some sources list five, but the dialects spoken in Maliku and Malé are almost identical.) These tend to represent different diachronical stages in the development of the language. In general, the more archaic dialects are spoken in the south. Officially, only the dialect of the capital, Malé, is written, but in practice this is not the case. The Addu dialect from the southern islands contains one sound [ɳ] which the other dialects do not use. An additional letter, naa, is used for representing this extra sound.