Tim wrote:

>Also according to my grammar, I have
>listed menninir and not mennirnir.

Jón Magnússon wrote:

"[M]annur, unde per analogiam linvgvæ facile
fit Nominativus Pluralis mennir. Sed hunc fuisse
evidentissime monstrat Declinatio Affixarum mennirnir.
Ex his duobus Nominativis, madur (sive mannur) et
mann, iidem obliqvi sunt, qvemadmodum a sonur et son,
vinur et vin. Huic astipulatur Dialectus Germanica,
männer, ut et aliæ, omnes n Nominativi servantes."

[Basically "Mannur should be an older form than
maður because the plural was mennir, this
is shown by the definite plural mennirnir.]

But this is probably a bit off:)

My books tell me that 'menninir' probably
became 'mennirnir' by anology with words
like 'gestirnir'.

When the change happened I don't know;
Jón Magnússon was born in 1662 so it must
be before that.

Oh, alright, the 13th century form should
probably be 'menninir'.

Are there other masculine words that end with
a stem consonant in the plural?

Regards,
Haukur