I checked Pekka Sammallahti and Klaus Peter Nickel's
Nordsamisk grammatikk, but there doesn't seem to be a chapter dedicated to the subject. However, I managed to piece something together.
Definiteness can be signaled through word order similarly to Finnish and Estonian, for example:
Áhkku lea goađis. 'Grandmother is in a/the tent.'
vs.
Goađis lea áhkku. 'There is a grandmother in the tent.'
PS and KPN call the former sentence type
lokaliserende setning and the latter
eksistentialsetning, which is akin to the classification of Finnish sentences in
Iso suomen kielioppi. The same applies to habitive sentences:
Máhtes lea beana. 'Máhtte has a dog.'
vs.
Beana lea Máhtes. 'The dog is with Máhtte/in Máhtte's possession.'
The use of demonstrative and indefinite pronouns is also a way to show (in)definiteness. However, the dual pronouns can't be used indefinitely, according to PS and KPN (my translation from Norwegian):
Dual is used only if the subject denotes two definite persons (seldom animals) or two people that have been mentioned before. Otherwise the predicate will be in plural.
Dual
Gea, do boahtiba Niillas ja Ovllá. 'Look, Niillas and Ovllá are coming over there.'
Dat guovttos eaba orron guhká dáppe. 'Those two didn't stay here for long.'
Beana ja vielppis leaba olgun. 'The dog and the puppy are outside.'
Plural
De bohte guokte olbmo. 'Then two people came.'
Eai guovttisge nagot loktet dan geađggi. 'Not even two [people] are able to lift the stone.'
Viesus leat guokte uvssa. 'The house has two doors.'
But unlike Finnish and Estonian, in Saami the genitive-accusative case is the only case for objects in all situations (numerals are a small exception to this). Although, my teachers have said it's not uncommon especially in Finland to see/hear sentences like "
Son osttii girjjit" (pro
girjjiid), which is structured like the Finnish equivalent "
Hän osti kirjat", but this is considered wrong from a prescriptive standpoint.