Collective Nouns in Adûnayân are an informal tense, where each noun represents all examples of a concept, unlike the normal plural form of a singular noun, which represents a select group of that concept. As they exist more as a tense of the normal singular noun representing the concept, than an independent word, they cannot be inflected in normal usage (though one may use the objective with it for a name if need be).
Due to its relative unimportance within the language, it is believed by some to exist either as a relic from one of the Edainic languages, or perhaps the result of influence from other widely spoken languages among the Númenóreans, such as Sindarin with its similar Class Plural tense.
Examples:
kulub, “all edible vegetable roots,” versus kulbu, “root,” or the plural form kulbî, “roots.”
gimil, “all the stars,” versus gimli, “star,” or the plural form gimlî, “stars.”