"Never assume everyone will speak English...." How very true. If the person did, that may not want to speak it with you. I've seen where (in 2017) the DB conductor came into the coach stood near to the table where I was sitting, near the door, made an announcement and explanation in German that due to the AC not working, DB was passing out water free as a way to relieve the discomfort...yes, it was getting a bit hot. The young Swedish guys sitting at the table asked the DB guy to repeat what he had just said in English. The DB guy looked at him and ignored him, said "free."
Most likely you would fine someone who has the level of English to communicate, or in central or east central Europe, they could ask/say they speak only German. I've had both experiences in Brno, Slavkov, and Prague and in Krakow. When the announcements are made in only one language, (they are sometimes), then that can get more difficult. That depends on the station, remote or busy, etc.