Ossetic "be"

"be" (momentary) in Ossetic
dæn
dæ
u, is, i

stæm
stut
sti

Anyone in cybalist have an idea what this is about?

The usual pres. ending are
-&n
-&s
-&

-æm
-ut
-&nts


I was comparing it in my mind to the Gothic preterite endings
-da, de:s, -da, de:dum, de:duT, -de:dun
if from
dhom, dheds, dhet, dhezdhm, dezdheT, dezdhnt
from
dhom, dhedhs, dhet, dheghdhm, deghdheT, deghdhnt

which is full of errors, but a beginning.

The Germanic pret. is a periphrastic ppp + aux verb in the present. Or?


Torsten