Sprache lernen im Vorübergehen!
An important way to increase your motivation for learning is to be aware of what you are doing it for. This doesn’t necessarily have to be the next class test. It’s true that you’re studying to get a good grade. But you can also give it an overriding goal, for example: I’m learning English so that I can go to school after the can go. Or: I hate engineering, but I really want to become an engineer later. With such goals, the learning makes sense and you know exactly what you are doing it for.