[Thursday 03 January, 2013]
No, this is not a dialect spoken by idiots. The prefix idio- means ‘personal’ in Greek - as in the word idiosyncrasy, which means a personal habit or eccentricity. An idiolect is your own personal dialect. It’s the kind of language which you - Jim, Jean, Mary, or whatever you name is - make use of, and which makes you different from everyone else. If you think about it, there are so many ways in which our vowels, consonants, voice qualities, words, and sentence patterns differ from person to person that you’d be very unlikely to find two people who had exactly the same way of using language. Everyone has their own idiolect.
There are many ways to check this out. Do you and your friends have exactly the same feelings about words and sentences? Which words do you like? Which do you hate? Which sound odd? Which are embarrassing? You’ll find many differences of opinion.
Or do this: choose a couple of pages from an advanced dictionary, and make a list of all the words which are defined there. Everyone has to say which words on the list they often use, which words they occasionally use, which words they never use but do understand, and which words they don’t understand at all. I should be very surprised if two people ever came up with the same results.
An idiolect is a bit like having your own linguistic fingerprints, really - except that you can imitate or forge language, but you can’t forge fingerprints.