In the languages of the arctic regions of the continent on which my conlangs reside, the following trait holds, except for the Tatediem tribes that have moved into the area fairly recently.
nouns:
subjects → mainly nominative
arguments → other cases
obliques → other cases
infinitives:
subjects → mainly nominative
arguments → nominative
obliques → other case
With other argument types, a number of arguments may have non-nominative cases. The most obvious examples would be the accusative, which in Ćwarmin marks the direct object, the pegative, which in Ćwarmin marks the subject of a ditransitive verb, and the dative, which in Ćwarmin and Ŋʒädär marks the indirect object. Several of the normally oblique cases also can appear as arguments of specific verbs, such as:
kəc-ite ostanc-ap dart-u
wall-DEF.NOM storm-instr withstand-3sg
the wall withstands storms
From Ćwarmin. 'ostanc-ap' is not an object - it does not pass objecthood tests; however, it is not in an adjunct relation to the verb either, as it does not pass such tests either. For instance, 'ostanc-ap' is not a permissible answer to 'kəc-ite terce dart-u', 'how does the wall withstand?', whereas adverbs of manner, instrument and similar are permissible as answers to 'terce'. For one, it's integral to the verb – although the withstood thing can be omitted, it still is implicitly there, and without an implicit noun phrase to which the listener can bind a null pronoun there, any finite sentence with dartan is malformed.]
äinäyi tunt'a-: k'ıʒo-lus
old.woman enjoy-intr game-to
(the) old woman enjoys the game
From Ŋʒädär. The intransitivity marker on the verb should indicate that k'ıʒo is not an object or subject, nor an indirect object. The case marking suggests a spatial reading but this is obviously not the case either. This also neither passes all adjuncthood or all objecthood tests, although it passes more objecthood tests than it passes adjuncthood tests. Similar things apply here as with the verb dartan in Ćwarmin.
Ərges simi p'arima-mai tuxa-ju
father son tradition-with teach
the father teaches his son traditions
From Sargaĺk. P'arima-mai is not a regular object, since in that case, Ərges would be in the pegative, and you'd have *Ərges-ta simi p'arima(-mai) tuxa-ju. Similar restrictions as in the previous two examples apply.
However, we find that all three of these can take naked infinitives:
kəc-ite atosćun dart-u – the wall withstands (for someone to) attack (it)
äinäyi tunt'a-: kılıs – the old woman enjoys singing
ərges simi garjir tuxa-ju - the father teaches his son to ask permission (before entering places)
However, other circumstances where these cases would be used, the infinitive would require the case as well, such as:
pər źil-ic kopon-ap śapr-u
man nail-acc hammer-instr strike-3sg
[Ćwarmin. The instrument is not an argument of 'śapran'. It would be a reasonable answer to the question "pər źil-ic terce śapr-u".]
pər-ite kəc-itiś arnjan-ap əmnit-i
man-def wall-acc.def hurry-instr build-3sg
the man builds the wall quickly
Now, we need to consider the notion of argument here. I distinguish, for these languages, two kinds of noun phrases in a clause - arguments and adjuncts. To understand the difference, we need to look at the mental record that a "verb template" is. Here's an example for some randomly imagined verb:
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Action: | (verb) |
Subject: | Agent |
(Object:) | Patient |
Oblique object: | Destination |
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So, the verb as different types of arguments, and each argument is a thing in this template. A location can be part of the template, but it needn't - all verbs can be carried out at locations, but only for some is the location part of the template. In some, the object might be filled out with a location, etc. Some verbs may have multiple permissible templates.
What happens in these languages is that an infinitive is assigned to whichever semantically reasonably likely slot in the template that it could imaginably fill, and there you go. Nouns, however, get case assigned by the slots. Adverbials are not assigned case by any system like this, but by a more 'universal' template, and therefore, any noun phrase that adds information in a clause beyond what the templates enable will follow more regular patterns. This 'universal' template has a wider range than does the verb template, and ends up forcing case marking onto infinitives outside of the range of the verb's 'gravitational pull'.