> I'm just reading "Sumerian mythology" by Samuel Noah Kramer. He
> claims that the Sumerians language was not related to indo-
> european or semitic languages, rather to the finish language
> family. Is this belief still prevalent among linguistics?

I believe the connections of Sumerian were regarded originally as
Turanian on the basis of the fact that both Turanian (now called
Turkic or Altaic) was also an agglutinative tongue. Perhaps the
connection to Finnish came from the theory that Turkic was a part of
the Uralo-Altaic Superfamily. Most researchers today also separate
Uralo-Yukaghir from Altaic languages.

Most linguists today hold that Sumerian was a linguistic isolate.

Hope this helps