I've never been in an abusive relationship. Although some of my relationships have been dysfunctional in various ways, I won't stand for abuse. I know the situations get complex and hard to get out of, but I can't say I really understand it because I haven't been there.
I've never been hit (play-fighting and wrestling around don't count) and as far as mental abuse goes, well, if you want to say something mean or raise your voice to me you'd better have a damn good reason.
I did have a neighbor once who behaved abusively towards me and boy did he pay for it...