Student or Learner
"I know you are blowing smoke. You don't have the nerve."
What does "you don't have the nerve" mean in this context?
You need to give us more of the context to get a full answer. Normally, "you don't have the nerve (to do something)" can mean that you are not brave enough, or that you are not cruel enough.
I'm not a teacher of English, but I have spoken it for (almost) all of my life....