When I took a TEFL/TESL course last year I got the list of the most common words in rank order. The same handout also said the 8 words are 33% of spoken English. I thought later, how do they know without some numbers attached? Most common means most used. So counts can be established but this is never done. What we get are statistical analysis like joint frequency. This corpus is taken on faith, we trust someone to do a good job. Where can we verify?
Most lists get the first eight words right, then after that it varies. How about some consistency? Google is consistent.
I suspect web companies use this system already but the
ESL world has declined to notice it.