@Setanta,
When one addresses the entire population of a nation, they obviously mean ''the majority'' of the specific population.
Not being able to tell the difference between ''could of'' and ''could have'' when someone says ''could've'' shouldn't be an excuse. The actual question is ''Why do they not learn that at school?''.
Like many comments mention, it is not meant to be a big deal. Though that is true (it not having to be a big deal), it actually is a big deal for people like me. People that have this thing that many people call OCD (though I don't think it is OCD), can't stand it when people say ''I could of been there'' or ''Your cute''. Also not using question marks, apostrophes and periods is a big deal to me. ''We done''. Is that a question or is it like, a statement?? Are you asking me if we are done or are you telling me we are done?? It is not only confusing but also makes me want to break the device I am using to read that.
Point being, don't be lazy. Use question marks, periods, apostrophes, commas and read books as I know the school doesn't do enough to make sure the teens know these things.
P.S. If my grammar is improper, I apologize as I am not from an English speaking country.