Apparently the oldest English words (according to Reading University researches) are “I”, “we”, “two” and “three” dating back tens of thousands of years, (40,000)…
Also they claim words such as "squeeze", "guts", "stick" and "bad" as likely to be extinct before others…
What the researchers found was that the frequency with which a word is used relates to how slowly it changes through time, so that the most common words tend to be the oldest ones.
For example, the words "I" and "who" are among the oldest, along with the words "two", "three", and "five". The word "one" is only slightly younger.
The word "four" experienced a linguistic evolutionary leap that makes it significantly younger in English and different from other Indo-European languages
The article on the BBC web site BBC NEWS | Science & Environment | ‘Oldest English words’ identified is very interesting for anyone interested in languages