And of course I should have written "…among the most fascinating aspects of any language."

When we speak of a bicycle fork in the USA and the front (or back) forks in Australia and England, we are not worrying about the correctness or otherwise of the term. Fork is strictly correct, but here we are entering the realm of colloquialisms, among the most fascinating aspect of any language.

Trousers comes from the Irish and Gaelic 'trews', scissors comes from Old French 'cisoires', which itself derives from Latin 'cisoria' the plural of 'cisorium', a cutting instrument. Because it came into English from the French, it retained the final 's'.

Well said, Kim.

Frank Merton states that "…breaking with unnecessary rules is cause for happiness… Rules that achieve nothing except make pedants happy and allow people to consider themselves superior to others (“educated”) are best abandoned.

Then goes onto write: "The purpose of language is to communicate. Therefore, clarity is the only valid reason for having a rule. I will admit that social convention dictates most of the rules I follow, since I am aware of the prejudices about this subject, but I think they are diminishing." These statements are almost at opposites.

The rules of grammar do achieve something, they allow for effective and clearer communication. The rules can – and are – occasionally broken for the sake of dramatic effect in writing, and bent where they need to be bent for appearances' sake, but all in all they work pretty well. Superiority and pedantics have nothing to do with it – the latter can sometimes be a good thing; would you, for example, criticise a judge whom you thought was being pedantic about the law when passing sentence on a drink–driver? Who knows?

Technically speaking, "who knows" should carry the question mark, but if you want to imply that it was uttered as a statement then your writing should reflect that. One of the curses of modern writing is the tendency to do away with vocabulary and description, narrowing everything down to one-liners and the lowest common denominator. Perhaps this offers more opportunity for the writer to flog work to teevee producers – almost as a ready made script – but it does nothing for the ordinary reader.

Oh, and in FM's statement "…but I think they are diminishing.", 'but' should be replaced by 'though'.

scyllacat is right. If the person being lied to doesn't believe what is said, then that person is not misled.

You could also have told someone what you believed was the truth when in fact you were in error, i.e. had your facts wrong. If you were believed then you would have misled them, albeit unintentionally.