In Dragon's Spire, I have got to the dragon and watched him kill Kol.
I approach and say "Elseramavin" to him and he responds with some blurb
about the sword. I then give hin the shroud which he takes and blurbs
some more. But ends with "Wait! You must speak the scacred word.".
Nothing I say seems to do (including Elseramavin again), and the doors
are not open. What do I have to do?

Tarweed,

This is a common problem that is (usually) easily fixed. It doesn't impress the old fellow if you type in the word - you have to select talk, and pick it from all your talking options - it's the only way he recognises it.