Not to mention thar/tha in Yorkshire which is a contraction of thou art!
Oh, how could I forget the one that pees me off most of all: People who pronounce "straight" as "Shhtraight". Mike Brewer is the worst but there are many others.
For those who think that RP is the only acceptable form of pronunciation I would recommend a look at some of these texts.
https://www.amazon.co.uk/s/ref=nb_sb...s+and+Dialects
They highlight the differences in dialect across Britain and how these differences came to be. Many examples of how old forms of words persist in local dialect.
This is a particular favourite of mine: https://www.amazon.co.uk/Atlas-Engli...glish+dialects
Geoff