<is i-umlaut the same as i -mutation?

<an example from old english being the verb cuman

<cume

<cymst

<cymþ
<it seems to me that in old norse it is only a half step.  instead of u -y it is u - ü.

<but this is only uneducated speculation.

<Jarrod
 

Yes, i-umlaut and i-mutation are two different terms for the same thing.

 

The quality of the vowel has nothing to do with the way it is spelt. I can’t remember ever seeing ü in Old Norse.

 

As far as conventional reconstructions are concerned Old English and Old Norse <y> and German <ü> are/were vowels of similar, if not the same pronunciation.

 

There is no ‘half-step’ involved.

 

Dan