I remember a documentary about CS - and Tony Warren saying how he listened to his mum and her friends talking when he was small, which gave him an over-riding sense of strong Lancashire women who became the backbone of his drama when he started to write it.
Then he heard someone refer to people from another street as " ... very bay window down there ..." - that's the sort of ear for dialogue that pins down an entire social class in five simple words.
You don't get that sort of ear for dialogue very often - Victoria Wood had it, Alan Bennett has it.