If you were planning to take a trip back in time to the Battle of Hastings, you would probably need to pack a phrasebook next to your suit of armour. If you think you’d be able to seamlessly integrate yourself with the people of the day without one of these to hand, you’d be sadly mistaken.

According to evolutionary language scientists, half of the words we use in daily conversation today would sound completely foreign to our ancestors 2,500 years ago. Even travelling back a thousand years ago, those from the 21st century would have a hard time making themselves understood.

A discovery by researchers at the University of Reading a few years ago certainly shines a new light on historical dramas such as Showtime’s The Tudors and BBC’s The White Queen. Indeed, should the real Edward IV and his wife Elizabeth Woodville tune in to watch the latter – which is based on the Philippa Gregory novel; itself based loosely on the lives of King Edward and Queen Elizabeth – they would have trouble keeping up with what’s going on. That’s because the language the modern day actors playing them speak would sound unfamiliar to what they are used to. And that’s before they even start to question how their modern-day counterparts have such white teeth and well-conditioned hair!

According to the scientists, who used a supercomputer to track the evolution of the Indo-European family of languages over the last 30,000 years, the oldest words still in use today originated 10,000 years ago. To put this into perspective, that’s around the same time humans evolved from a life as hunter-gatherers to settling in small communities; a period which is generally seen as the birth of civilisation.

‘Who’ is the oldest word still in use today, according to the research. This is followed by ‘two’, ‘three, ‘I’ and ‘five’. The reason so many numbers appear is that numerical words, along with pronouns, are used the most often. As a result, they are less likely to evolve.

Meanwhile, adjectives change much more quickly and conjunctions and prepositions evolve the fastest. Because of this, they are also the words likely to drop out of use the quickest. For instance, the scientists revealed that the word ‘throw’ has a half-life of 900 years, so unless a concerted effort is made to preserve it, it will probably be replaced in the next 10,000 years.

Professor of Evolutionary Biology at the University of Reading Mark Pagel said: “If a time-traveller came to us, and told us he wanted to go back to that period, we could arm him with the appropriate phrase book, and hopefully keep him out of trouble.”

Mental Floss‘ Arika Okrent this week compiled a list of some of the oldest words in the English language that have been preserved because they feature in popular idioms. Despite these words being close to obsolete in day-to-day conversation, they remain in limited circulation thanks to these sayings.

Among the survivors are ‘deserts’ as in ‘just deserts’, which means ‘that which is deserved’ or ‘to get one’s dues’. Other words to have survived in this way include ‘sleight’ as in ‘sleight of hand’, ‘lurch’ from ‘in the lurch’ and ‘umbrage’, which means to cause offence; although today we are more likely to use it to describe someone who has taken offence.

Just as old words die out, new ones are evolving all the time. In March this year, the Oxford English Dictionary added ‘cred’, ‘clunker’, ‘gangling’ and ‘defriend’ to its pages.