stubborn, obstinate
Du warst so starrköpfig und wolltest nicht ohne deine Klassenkameraden gehen.
You were so stubborn and didn't want to leave without your classmates.
— The Flowers of War (2011)
Tom war starrköpfig.
Tom was stubborn.
Don't be so stubborn!
Maria war starrköpfig.
Maria was stubborn.
Tom ist starrköpfig.
Tom is stubborn.