This time I'll discuss the conjugation of verbs with respect to grammatical person. In Swedish dialects and folk traditions 2004 (ed. Maj Reinhammar) I noticed the verb form vilin [ˈʋɪˑlɪn] 'want' (second person plural). The part of the 52 lines long poem where vilin is mentioned goes like:
Såm skä nöna sta igen
Å krus tä Mass Jansa Jlin,
Å ha bydi Hössbonn sänn
Frila bö däck, dä da vilin
(where "Jlin" is read as Ilin [ˈɪˑlɪn], the colloquial Jamtlandic form for Helen) with the more or less literal translation
Which will now go away again
And cookies to Matt Johnson's Ellen,
And has invited her master
Much was offered to you, that you want
There are two things which are interesting about vilin. Namely, the ending -in rather than -an, and the fact that it's not an imperative mood but in indicative. Note that today the ending in question is exclusively -an, and verbs are only conjugated with respect to grammatical person in the imperative.
The ending -in is of course the old one, but is a more modern form than Old Norse -ið. Indeed, in ON, vilin would've been viljið [ˈwɪɫɪ̯ɪð]. The 18th century form vilin probably comes from an older vili [ˈwɪlɪ] with a dropped -ð (ON ð after a vowel has always become silent in Jamtlandic). An -n has been added, probably with Swedish as a rôle model. (In slightly outdated Swedish it'd be viljen, from Old Swedish viljin.) The reason is probably to avoid ambiguities due to converging pronounciations. For example, ON kastið 'throw' (second person plural) would straightforwardly have become "kasteð" [ˈkastə] in Jamtlandic, which would be the same as the imperative and the past participle. It's obvious that the -n was added at a late stage since otherwise one would end up with "vili" and "kasta" due to (at least for the latter) nasalization, opening and dropped -n. I would definitely suggest that old short stemmed verbs get -in (like e.g. vilin, since vil was a short stem) and old long stemmed verbs get -an (like e.g. kastan, since kast was a long stem).
The other thing to discuss is the fact vilin isn't used as an imperative in the poem, but as an indicative. It's apparently the fact that in mid 18th century Jamtlandic, at least sporadically, one could conjugate a verb in the indicative mood with respect to grammatical person. Today this is only the case for the imperative mood, and even though it's standard in the second person plural, it's not in first person plural. One evidence that it still exist is the following quote from p. 99 in the PhD dissertation Om dativ i svenska och norska dialekter: 1. Dativ vid verb by Maj Reinhammar (1973):
Lyckönska: lyckönschom nu bröfoLkom Mörsil
which translates to 'Let us congratulate our brother nations!' In standardized spelling, the first person plural ending would be -um. My suggestion is that, since it was possible in 18th century Jamtlandic (which I count as Late Modern Jamtlandic, the period 1700-now i.e. the period for which Jamtlandic has been studied by scholars), it should be possible to conjugate verbs with respect to grammatical person.
As an example, take the verb kaste 'throw'. Followin the prescription above, the "light" (modern) conjugation pattern for the indicative mood would be
while the "heavy" (archaic) conjugation is
Sg. kaste kasteð
1st Pl. kastum kasteð
2nd Pl. kastan kasteð
3rd Pl. kaste kasteð
(The imperfect tense has a single conjugation for this specific class of verbs. Other classes of verbs have a "full" conjugation pattern with respect to grammatical person.) For the imperative, I think it's a good idea to impose the special first person plural as standard, giving
Sg. 1st Pl. 2nd Pl.
Kast! Kastum! Kastan!
This concludes the post.