My father is in the military. I remember as a young kid moving to Germany with my family for my dad's job, and my parents enrolled me in a German after school. But the language barrier and culture shock was too much for my little kid self, and my parents put me in an international school.
Same experiences happen with refugees coming to different countries. The kids coming in cannot speak the languages, they don't understand the culture, or how things work in the new school.
So Germany took action to help these kids, by recruiting 8,500 special teachers to help refugee children in their own programs. These school programs help kids like this catch up to their peers.