This is just an academic/hypothetical question really, I'm not in a verbally abusive relationship at the moment.
In this book by Patricia Evans, she said that if we want a verbally abusive partner to change, we could write/say something like this:-
'I will not be responding to you in the usual way. I'm not happy with some of the things I've heard from you. I want to have a really good relationship with you. I would like to see some changes in communication. In the past, I've tried to explain to you what bothered me about some of your behaviours. I do not feel that I have been successful. I assure you that I will be letting you know what I want and what I don't want in our relationship; I have limits and I will let you know immediately if you overstep them. I ask for your co-operation.'
How often do you think this will make a partner stop his abuse? It doesn't seem very likely to me. I don't think they'd take it well.
I suppose maybe it is a last ditch attempt.