While category of number exists in majority of languages of the Earth, it is not native to Black Speech. It's believed by some linguists that it was absent in Black Speech. This opinion is based upon using the word “Nazgûl” as both singular and plural noun in “The Lord of the Rings” trilogy. The other reason is the popular belief that Sauron suppressed individuality and forbade to use the word “I” or even any other singular pronoun. This resembles dystopian novel "We" (1921) by Yevgeny Zamyatin. However from LOTR it's clear that Sauron failed in organizing orcs who regularly quarrel with each other and put their personal wishes above the order (i.e. scene of Merry and Pippin escaping orcish capture), so it's assumed that orcish dialects have category of number.

Nouns, adjectives, 1st and 2nd person pronouns do not have category of number in Nûrlâm or have general number to be more precise. By default they are translated as plural, so there is no distinction in countable and uncountable nouns. Therefore exact numbers (like in ash nazg) and quantifier words (i.e. equivalents of English some, few, many) are used more often than in typical European languages. However, verbs can carry information about number of subject in 3rd person and of object if it's 3rd person clitic pronoun.

In Orcish dialects (like Shadowlandian) unanimated nouns have singular and plural form, animated nouns have one form for both (which is often ignored in colloquial speech where there is no distinction in animacy). But Adjectives have plural form despite animacy of connected noun. Pronouns have plural form. Verbs have special 3rd person plural suffix -ut. Plural suffix is the same for nouns, pronouns and adjectives. In Shadowlandian and Horngoth it's -u and -i in Svartiska and MERP. Nûrlâm suggests using -û (taken from rare Svartiska variant) to avoid confusion with preposition meaning “to”. If word ends with a vowel than plural suffix is -z in all dialects.

Some dialects consider suffixes -ûk (all) or -hai (folk, people) as collective plural. Nûrlâm treats them literally and without any special grammatical meaning.