differences between the East End and the West End, there have traditionally been sociolinguistic differences between the two parts of the city. The colloquial language of the East End is based on the Oslo dialect (austkantsmål), whereas the colloquial language in the West End is based on the educated bokmål (riksmål) of the upper class, which has evolved into today's standard variation of eastern Norwegian. There have therefore been two colloquial languages in the city side by side for a long time, with a significant division based on social differences. There are furthermore differences between the dialects and the sociolects in the East End and the West End, but the most characteristic parts, especially in the East End language, are in the process of being disused, with the general development that affects the entire eastern part of Norway, where local dialects and sociolects are threatened by the standard variety of eastern Norwegian. Increased education levels, higher use of mass media and higher social mobility help towards this development.A-endings ("gata"), diphthongs ("aleine", "blei"), the thick l and stress on the first syllable ("bannan") are traditional signs of the East End language. The West End language, based on educated bokmål, has the utrum and en-endings (masculine endings on feminine words, such as "gaten" rather than "gata"), significantly fewer diphthongs ("alene", "ble") and other expressions and also a partially different vocabulary than the East End language, basically a language that is more like Danish in most of the districts. The West End language has also changed in the past years, but less so than the East End language, with for example higher tolerance for a-endings on some words. The most formal forms of language and conversation in the West End are seen as old-fashioned by many young people. , almost every citizen below 25 years pronounced the city's name as /uʃlu/, rather than /uslu/. In the West End, 90 % of the age group between 25 and 50 of the women and 63 % of the men did so. For many decades, this pronunciation was limited to sociolects in the East End. Characteristic forms of language in Oslo are on their way to becoming disused, for example forms such as "a'Kari" and "n'Per". In the East End, the Oslo Metro is colloquially called banen ("the rail"), which stems from official name T-bane (t for tunnel), coined in the 1960s. In the West End