I from the stone age

Some of the oldest words in the English language were probably used by our ancestors in the stone age. Mark Pagel of the
Reading University in the UK believes that words such as "I", "we", "two", "three" and "five" were used 20,000 years
ago.

Pagel, an evolutionary biologist, used a powerful supercomputer to track the evolution of words in the Indo-European family
of languages back through about 20,000 years.

The researchers could work out how old a word is by comparing it in languages that share a common heritage. They are also
able to work out which words are likely to disappear in the future. For example, there are 46 different ways of saying
'dirty' in the Indo-European languages. This means that it is unlikely to survive the next 1,000 years in its present form.

Pagel's team uncovered a few other simple rules--numerals evolve the slowest, then nouns, then verbs, then adjectives.

Conjunctions and prepositions evolve the fastest, some as much as 100 times faster than numerals. Fifty per cent of the words
we use today would be unrecognizable to our ancestors 2,500 years ago, Pagel said.