In the course of my Swedish studies, I have discovered the archaic form I KALLEN. I understand that "I" meant "you (pl.)" and that the verb, e.g. KALLA (to call) had a special ending in -EN, which seems to have applied across all the conjugations except contracted verbs like TRO.
I have a smattering of Icelandic, which is close to Old Norse, but the corresponding form there is ÞIÐ KALLIÐ, which doesn't seem to fit the bill. Please, can anyone enlighten me as to the ultimate source of I KALLEN? I mean both the pronoun I and the ending EN.