How lingQ count the number of known words?

Hello. I would want to know, please, how lingQ counts the number of known words.

For example :

  • ( I) run and (he) runs: is it counted as two words (run+runs) on one word only (to run verb)?
    -Plane and planes is counted as two words or one word only by lingQ

Because it is not the same thing.

Thanks for your help and thanks very much Steve, i’m a great fan of you and your method.

Run and Runs, as well as Plane and Planes would be counted as two known words by our system.

Thanks for your answer Zoran