Inflection of agglutinative and fusional elements: Nouns
Before continuing on, I would like to reiterate the difference between agglutination and fusion, agglutination uses multiple separate morphemes with each morpheme representing a separate piece of information, while fusional morphemes contain multiple meanings, such as plurality, grammatical gender (in languages that use this), and case inflection, all in one.
Perhaps one of the easier examples to demonstrate, of Ossetian's use of agglutination, is the plural marker '-T-'. While representing plurality in nouns, it does not give context beyond that, and requires additional morphemes to convey extra information.
Taking an example from the above link, I will explore the system of inflection as it appears in the different cases for nouns:
The example word is 'сæр' (head).
Nominative: - сæр - сæртæ
Genitive: - сæры - сæрты
Dative: - сæрæн - сæртæн
Allative: - сæрмæ - сæртæм
Ablative: - сæрæй - сæртæй
Inessive: - сæры* - сæрты*
Adessive: - сæрыл - сæртыл
Equative: - сæрау - сæртау
Comitative: - сæримæ - сæртимæ
* The case-inflection for the genitive and inessive cases is listed as being the same, context will inform you what form is being used.
I mentioned that the '-T-' plurality marker is the standard marker in most cases, some of the situations where other markers are used include:
Within what Abaev categorizes as 'kinship terms', some specific words inflect differently than normal, by adding an 'æлтæ' plural-marker, with examples attested as 'мад' ('mother', singular) and 'мадæлтæ'' ('mothers', plural), 'фыд' ('father', singular) and 'фыдæлтæ' ('fathers', plural), and lastly, 'æрвад' (relative, singular) and 'æрвадæлтæ' (relatives, singular).
Listed in Abaev's work is several examples where specific nouns don't inflect in a manner that you would expect them if they followed the general pattern:
Ус 'woman' is marked in the plural as 'Устытæ'; basically, the plural is marked as if the stem word was 'Уст', but because it is not, in theory, the plural should technically be marked as 'Устæ'.
Хъуг 'cow', theoretically, should be marked in the plural as 'Хъугтæ', however the plural in this case is marked as 'Хъуццытæ'.
фыр 'ram', is marked in the plural as 'фырытæ', despite the fact that the regular pattern would theoretically mark it in the plural as 'фыртæ'.
куыдз 'dog' is marked in the plural as 'куйтæ' (куыйтæ) instead of 'куыдзтæ'.