What is the use of "wouldn't" in this sentence?
"I was trying to get to sleep, but Jimmy wouldn't stop talking"
Thanking you Scottish
Would is the past tense of will. In other words, he wasn't going to stop.
Also, the past tense form can express the subjunctive mood, as in "would you?", so "he wouldn't" is just the negation. But this is a slightly more complicated interpretation, not to say ambiguous.