These are, unfortunately, horrible grammar examples brought about by uneducated backwater collequalism. When people correct it, they are seriously doing you a favor, because when you speak in that manner, or type it in that manner, it makes you look extremely uneducated.
Some examples for your educational use:
I seen my baby daddy getting it on with Darlene.
I saw my daughters father cheating on me with Darlene.
We was at the Piggly Wiggly for some pork rinds when I seen my food stamps was gone.
I was at the grocery store when I realized I didn't have enough money to purchase the items I needed.
Take a moment to read the above 4 sentences if you have ever been corrected on the was vs were or seen vs saw. Only 2 of them are grammatically correct.