To learn German quick and easy you have to be a little stubborn. So here is how you can express stubbornness using the following words:
Starr, stur, störrisch, starrköpfig, starrsinnig and halsstarrig.
All of these words are distantly related to the English words “stare,” in the sense of an unmoving gaze. They also relate to the English word "stern" and refer to a self-willed, “mulish” or pig-headed being or action.
Words like dickköpfig (literally “fat-headed”), trotzig and eigensinnig also fit into this category.
The word hartnäckig can be used when someone clings to an opinion (in other words, one would not necessarily use this word to describe a donkey) or refuses to give up.
This is also the word one should use to describe stubborn stains.
Sie haben sich hartnäckig geweigert. They stubbornly refused.
Sie können selbst hartnäckige Flecken entfernen. You can even remove stubborn stains.
Er macht stur weiter. He’s (stubbornly) carrying on regardless.
Das ist ein störrischer Esel. That’s a stubborn donkey.