written formal english is written and formal.
in practice 'me and my whoever' <verbis often what one hears.
and if you correct everyone who speaks in that dialect
you are a jerk and a bit of a control freak.
UNLESS you are an English teacher or they instructed you to help them learn formal English.
in fact, the correct behavior in a polite situation is that unless you really do not understand what the person has communicated you do not correct them unless, as I said, you are their teacher, or parent, teaching them the formal way to speak.
there is a difference between descriptive linquistics and perscriptive formal langauge.
The real langauge that people use on the streets, in the factories, in the forest, on the mountain, often differs (always differs) from that which is used in formal contracts or written discourse.