Everyone in Moscow speaks Russian and a lot of people speak basic English. However, no one in the international dorm spoke English! It was very scary going to do laundry and being yelled at by a scary Russian lady who would then laugh, which was even more confusing because I had no idea what she had said! There are other foreign exchange students at my University, some who study full time, and some who are only there for a semester as well. It is very common to hear French, German, Italian, Hindi, Chinese and other languages in the halls of the international dorm.
Russian currency is called rubles. There are singular, five and ten ruble coins. Paper money is reserved for amounts of 50 and higher (50, 100, 500, 1,000, 1,500). There are no coins smaller than one ruble, but it is very uncommon to find anything for less than 10 or 20 rubles.
The price of water can vary. Because Moscow and St. Petersburg are old cities, they do not recommend drinking unfiltered tap water, so most people buy a filter or bottles of water. At the grocery store, you can get water for as cheap as 20-30 rubles, or about 50 U.S. cents. At a restaurant, you could pay as much as 150-200 rubles or about three to four U.S. dollars for water. They don't have free water at restaurants.
