Learning language is a complex process, not least because the English language seems to be full of exceptions - but understanding the difference between language and writing helps to explain some of those problems.  Our alphabet only provides an approximation to language, and sounds and letters do not always match.

Take the specific example of 'a' and 'an'.  Early on we are taught that 'a' is used before a word beginning with a consonant, and 'an' is used before words starting with a vowel.  Just as we've learned this rule, we suddenly find that there are exceptions!

• An honourable person
• A universal truth
• A one off charge
• An hour ago
• An MMR injection

In actual fact, there is a rule with no exceptions, but it is distilled to sounds and not letters - language and not written interpretation.  The rule is:-

'a' is used before vowel SOUNDS, 'an' is used before consonant SOUNDS

When we pronounce 'honourble', we drop the 'h' and use an 'o' sound at the start of the word.  When we say 'MMR' we start with the vowel sound 'em' which DOES begin with a vowel.  With this understanding, there are no exceptions to the rule of when to use 'a' or 'an'.

The written English language uses 26 letters, but there are 44 sounds.  You've probably seen funny symbols, some of which are regular letters, used to display the pronunciation of words in a dictionary, for example:-

dictionary
dɪkʃəˌnɛri

These are phonemes, of which there are 20 vowel sounds and 24 consonant sounds in the English language (with additional marks to signify stress).  For a full chart of phonemic sounds, click here.  The more you look at language, the more clear it becomes that the written language and spoken language are two pretty different things, but for all its simplification, we're glad to have just 26 letters in our language rather than the estimated 47,000 characters of traditional Chinese!

Children say the funniest things as they learn language and start speaking for the first time. Toddlers learn language simply by listening to spoken words all around them, and sometimes they mis-hear what has been said. This can give rise to mispronunciations 'sticking', for example spaghetti is often misheard as 'sketty' and we've heard 'gescalator' for 'escalator' and 'ninner' for 'dinner'! Toddlers learn language at a phenomenal rate, far surpassing the capabilities of the most advanced supercomputers. However, it's not true that young toddlers learn language through watching television. Recent studies suggest that until the age of two, babies don't associate words that they hear on the TV with objects outside of the TV in the real world. This means that although they may be shown a picture of a 'spoon' and hear the word repeated, they won't immediately make the link with a spoon right next to them, until they are a little older.

One of the most amazing capabilities that children have is the way that they learn what a 'dog' is, and then are able to look at a photograph of a dog, see a real dog and even see a cartoon drawing of a dog and associate all of these as being dogs.  Try teaching a computer to do the same and you'll be training it for years!