In normal conversation we speak at a rate of about 300 syllables a minute. To do this we force air up through the larynx --- or supralaryngeal vocal tract, to be technical about it --- and, by variously pursing our lips and flapping our tongue around in our mouth rather in the manner of a freshly landed fish, we shape each passing puff of air into a series of loosely differentiated plosives, fricatives, gutturals, and other minor atmospheric disturbances. These emerge as a more or less continuous blur of sound. People don't talk like this, theytalklikethis. Syllables, words, sentences run together like a watercolor left in the rain. To understand what anyone is saying to us we must separate these noises into words and the words into sentences so that we might in our turn issue a stream of mixed sounds in response. If what we say is suitably apt and amusing, the listener will show his delight by emitting a series of uncontrolled high-pitched noises, accompanied by sharp intakes of breath of the sort normally associated with a seizure or heart failure. And by these means we converse. Talking, when you think about it, is a very strange business indeed.
From Bill Bryson's 'Mother Tongue: The English Language'.