Nominative plural of nouns

You already know that a Serbian noun tells you its gender through its ending: a consonant means masculine, -a means feminine, -o or -e means neuter. The plural works the same way — you change that ending. And because the three genders have three different endings, the plural you build depends on which gender the noun is.

So there is no single word for "the" or "a" to worry about, and nothing like English -s that fits everything. One book is knjiga, several books are knjige. One window is prozor, several windows are prozori.

Masculine: add -i

A masculine noun ends in a consonant. Put -i straight onto it and you have the plural.

• prozor → prozori (window → windows)
• računar → računari (computer → computers)
• profesor → profesori (teacher → teachers)
• ormar → ormari (cupboard → cupboards)

Short masculine nouns grow a syllable

Masculine nouns of one syllable usually do something extra: before the -i they insert a whole extra piece, -ov- or -ev-. Sto (table) does not become stoi — it becomes stolovi.

• sto → stolovi (table → tables)
• zid → zidovi (wall → walls)
• list → listovi (sheet, leaf → sheets)
• čas → časovi (class, lesson → classes)
• ključ → ključevi (key → keys)

The choice between -ov- and -ev- follows the sound at the end of the word: after the soft consonants č, ć, š, ž, j, lj, nj, đ and c you get -ev-, everywhere else -ov-. That is why ključ gives ključevi but zid gives zidovi.

Do not try to work out which short nouns take the extra syllable and which do not — it is simply part of the word, and the dictionary records it. Learn sto → stolovi the way you learned sto itself. Longer masculine nouns almost never do this: prozori, never prozorovi.

k, g and h change before -i

When a masculine noun ends in k, g or h, that consonant softens in front of the plural -i: k becomes c, g becomes z, h becomes s. This is about sound, not about meaning — Serbian simply avoids the sequence ki here. A noun like đak is one syllable, yet it does not take -ov-: it takes the plain -i with softening, and the plural is đaci.

• đak → đaci (pupil → pupils)
• učenik → učenici (pupil → pupils)
• nastavnik → nastavnici (teacher → teachers)

Feminine: -a becomes -e

A feminine noun ends in -a. Swap that -a for -e. Nothing is added and nothing softens — this is the easiest of the three.

• knjiga → knjige (book → books)
• olovka → olovke (pencil → pencils)
• stolica → stolice (chair → chairs)
• sveska → sveske (notebook → notebooks)
• tabla → table (board → boards)

Neuter: -o or -e becomes -a

A neuter noun ends in -o or -e. Either way, the plural ending is -a.

• slovo → slova (letter → letters)
• mesto → mesta (place, seat → places)
• pero → pera (pen → pens)
• pitanje → pitanja (question → questions)

A neuter plural in -a looks exactly like a feminine singular in -a. Pitanja is "questions", not "one question" — what tells you is the singular you already know the word by. Meet the word as pitanje, and pitanja can only be its plural.

All three side by side

The verb follows

When the subject becomes plural, biti moves from je to su, and from nije to nisu — exactly the forms you already know for oni.

• Olovka je ovde. → Olovke su ovde. (The pencil is here. → The pencils are here.)
• Prozor nije veliki. → Prozori nisu veliki. (The window is not big. → The windows are not big.)

A few Serbian nouns exist only in the plural, and vrata (door) is one of them. One door is vrata and two doors are vrata, always with su: Vrata su ovde. Treat it as a word that came ready-made plural.