Lately I stumbled across a sentence where one person was talking to another person and used
But you was thinking about it!
I'v always used "But you were ..." in this case and assumed that it just was a mistake or a joke I didn't get (as a non-native speaker). However, I stumbled across a similar case again today! Were I living a lie?
An earlier question on EL&U, Historical usage of "was"/"were" with "you", asks about this usage during the American Civil War, whereas the current question is about contemporary usage. However, Peter Shor's answer to that question mentions contemporary usage.