Because of a low literacy rate among the public (about 2–3% until the early 19th century and just about 15% at the end of 19th century),[citation needed] ordinary people had to hire scribes as "special request-writers" (arzuhâlcis) to be able to communicate with the government. The ethnic groups continued to speak within their families and neighborhoods (mahalles) with their own languages (e.g., Jews, Greeks, Armenians, etc.). In villages where two or more populations lived together, the inhabitants would often speak each other's language. In cosmopolitan cities, people often spoke their family languages; many of those who were not ethnic Turks spoke Turkish as a second language.
What was the second language of those that weren't ethnically Turkish?
Turkish