I shout Durn, to come to Tamriel, but it won't work. I did it at throat of the world, and other open areas. Why won't it let me get him?
This shout requires you to use all three words to actually summon him while aiming at the ground like most summoning spells. Be aware that even then you have to have enough open flat space.. which is actually pretty hard to come by.. Try it out in the fields near Whiterun just to be sure nothing else is in the way... and be careful.... You can easily piss the dragon off by hitting it or its minions... You do not want a pissed off Durnehviir.. trust me.