German is the main language spoken here in Berlin, but many people are also fluent in English, so it is fairly easy to navigate without speaking German fluently. But knowing the language definitely does help! Berlin also has a large Turkish population, so you will also hear Turkish throughout the city.
The euro is the currency used here. It is the same currency used by many other countries in Europe.
A bottle of water is typically €1.20, but in more touristy areas it tends to be a bit more expensive. At restaurants, water is usually also expensive because the tap water here is very good, so it's the norm to fill up your water bottle in the bathroom.
The best meal I had this week was Tteokbokki I had during a trip I went on with my German class to the market. Tteokbokki is a South Korean dish, made from stir-fried rice cakes, usually covered with a spicy sauce. At the market, we put our German to use by finding different vegetables and fruits, and ordering in German.
