There's all sort of common mistakes that seem to become part of the language, like 'could of done it' instead of 'could have done it'. I try not to be too much of a pedant.
The bald guy from Princess Bride was in Young Sheldon recently. Inconceivable!
Inconceivable indeed! He just be right old by now!
Could of, oh yes, that's another. I sometimes revel in the pedantry although I have given up with there/their/they're and the like as no one cares anymore. Truly language does evolve!