"Jein" is definitely one of the best words in the German language. It's one word for both yes and no.
ja + nein = jein
Knowing the word "jein" in German opens up a whole new world for German learners and their eyes get really big and their ears perk the first time they hear the word. "Jein" also has several uses; for starters, "jein" allows you to give two simultaneous answers to one question.
This is perfect for difficult questions and for difficult answers.