I've been watching a TV sitcom lately, "Last Tango in Halifax." A main character uses "weren't" instead of "wasn't" and I am wondering if that is considered correct in some areas or dialects? For example, "It weren't like that," or "I weren't going to stop there today." (As an American, British terminology sometimes sounds odd to me; especially the slang - which I usually find spot-on, witty and/or damn funny.)
This show isn't like a "Beverly Hillbillies" type; the characters aren't uneducated bumpkins. So my question is whether or not weren't can sometimes be interchangeable with wasn't, and if so, when? And is it a regional thing?