Why Can't The English ( or anybody else for that matter ) teach their children how to speak?

If I have to listen to another sports person say 'you know' I may throw up! When their parents and teachers are going to such trouble to make them accomplished tennis players or - I was going to say football players but maybe we shouldn't go there - or any other accomplishment which may involve speaking to other people, either millions or one, can they not teach them communication, other than by bloody phones? I would give the poor little buggers elocution lessons. Oh God, that sounds posh.
We must teach our children how to talk to one another, how to get up and speak in front of others, how to breathe.
I had a teacher once who made us stand up one by one and speak on a given subject, a bit like that Programme on Radio 4 and every time we said 'like' or 'you know' the rest of the class would raise their hands.
And please, mostly women, do stop talking down to your lap and try to project without shrieking.
I blame the BBC.  Even somebody as articulate as Roger Federer must be fed up by now of those dreadful interviews after every match he wins. What can you say other than 'I won because I played better than the other guy' or 'I lost because the other guy played better than me.'
And God help us, the interviews on television after they have been given trophies. Please, don't do it to them or to me. It's cringe making!!
If you can't be John McEnroe, who seems to communicate at the same level as his tennis when he was at his best, please folks just shut up and get on with it.
And since we are on the subject, no matter how intelligent people are they keep saying 'you and I.' God Almighty. It's 'you and me.' I has no business at the end like that!!!!  Grrr.
Now I shall take my pedantic self off because I am in danger of turning into the woman who wrote Eats, Shoots and Leaves or however it is. I hate a pedant most of all so I shall go and have lunch and try to remember that I'm not so good myself.