Yes, I agree. Although there is some semantic overlap, skills are more about practical, hands on kind of knowledge while "Kenntnisse" are more theoretical in nature. "Fertigkeiten, Fähigkeiten, Geschick" are better fits for 'skills'. I can have a lot of Kenntnisse about singing without getting a single note right in a performance. You probably wouldn't call me a skilled singer then... I have no issue with translating 'language skills' to "Sprachkenntnisse", though. As I said, there surely is some semantic overlap.
A native speaker told me that Wissen is more knowledge in the way of facts, but Kenntnis is your own conclusion on something. He mention something about an encyclopaedia called 'The great book of knowledge', and that he would always translate knowledge there as Wissen. He emphasised, though, that it was a very subtle difference.
Thank you! Your explanation helps!
As "science" is die Wissenschaft, this is how I will remember it as factual knowledge. And die Kenntnis more like personal or practical knowledge or understanding.
Maybe a little practice will make it easier to make the distinction as you say it is subtle. :)
Duolingo needs to do a better job of explaining the difference between Kenntnis, Kenntnisse, and Wissen. The trial and error method is not very effective because when I translate Kenntnis or Kentnisse as skill or skills, it is counted as incorrect and I am told that the correct translation is knowledge, but if I translate either as knowledge, it is counted as incorrect and I am told that the correct translation is skill or skills. How am I supposed to know in any particular situation which translation is correct?
So what would be the plural of kenntnis? "The skills" is not an acceptable translation, apparently.
I don't think "understanding" is a good translation of Kenntnis.
The main use, I think, is Kenntnis haben von etwas "to know about something" i.e. to have information about something that has occurred, to be aware of something, and similarly mit/ohne die Kenntnis von X "with(out) X's knowledge".