There are only three simple rules for pluralizing nouns.

Names for races or people are never pluralized.  For example, the word Nazgûl is both singular and plural.  The word Uruk is both singular and plural.  If you wanted to say “bring the three uruk,” you would simply say, “Thrak Uruk gakh.”  If you are talking about an entire race of people, use the suffix  –hai, which means peoples or folk.  So uruk-hai means “the uruk-people,” olog-hai means “the troll-people,” and so on.

**Please note:  Because words like snaga (slave), durub (ruler), and sharlob (human female) refer to people, you would not pluralize them.  So snaga is singular and plural.
 

Nouns ending in consonants become plural by adding “u” (note that this is the short u, not û).  Nazg, (ring) = singular, nazgu = plural.
 

Nouns ending in vowels become plural by adding “z”.  (goi = city, goiz = cities).  There are very few Black Speech nouns that end in a vowel.
 

Exercise
Pluralize the following nouns:

goi (city)                       lug (tower)             golug people (elf)

mau (warrior)**            hont (hand)              goth (lord)**

mokum (hatred)            ronk (pit)                  horn (beast)

sharkû (old man)         shara (human man)            olog (troll)

duf (knife)                     krimp (rope)               ufum (fear)

** note that words for people, like warrior or goth, do not take a plural.