German isn't that spread in the world as English or French, so you can count on that if you speak English, you will be understood as Germans all speak English (as the opposite to France)
Students will all be able to talk to you but people who went to school in East Germany before the '90s will most likely not have learned English. Due to the fact that most adults never used English outside of school and have never used it afterwards they, too, will be unable to speak English.
