fearful就是惊恐
eg:
The movie is so fearful that I can't continue to watch...
nervous就是紧张不安,害怕胆怯(表演前的心情)
Don't be nervous before your examination,it's just a piece of cake
He would be nervous of going too near the wild animals
afraid就是担心(同时也可以表达fearful的恐惧)
I am afraid of watch the fearful movie...
I am afraid that I am gonna fail this course...
ps:还有例如scare,jittery,tense,strained