-и / -е / -а

The nominative plural marks multiple entities acting as the subject of a sentence, or standing as predicate nouns after the copula бити. It is the default plural form for both definite and generic plural subjects when they are not quantified by numerals (which govern paucal forms for 2–4 and genitive plural for 5+) or quantity expressions.

1. Masculine Nouns
• Ending in a consonant: Most masculine nouns of two or more syllables add -и: прозор → прозори (windows), студент → студенти (students). Important patterns to remember:
  - Demonyms and nouns ending in the singulative suffix -ин (including words like грађанин) drop the suffix in the plural before adding -и: Србин → Срби (Serbs), грађанин (stem грађан-) → грађани (citizens).
  - The everyday word for "person/man" is irregular and suppletive: човек → људи (people).
• Masculine nouns ending in -о (from historical -л): Some masculine nouns end in -о in the nominative singular because final -л shifted to -о. Before plural endings, the -л- returns:
  - Stems with fleeting а like посао and угао lose the а in the plural (stems посл-, угл-), leaving a single-syllable base that takes the long plural suffix -ови: посао → послови (jobs), угао → углови (corners).
  - Truly monosyllabic stems like сто (stem стол-) also take the infix: сто → столови (tables).
  - Stems that stay multisyllabic like анђео (stem анђел-) simply take regular -и: анђео → анђели (angels).
• Monosyllabic masculine nouns: Most one-syllable masculine stems take the "long plural" (проширена множина) by inserting -ов- (or -ев- after soft consonants ј, ч, џ, ш, ж, ћ, ђ, њ, љ as well as ц) before -и: град → градови (cities), брод → бродови (ships), чај → чајеви (teas).
  - Fixed-stem monosyllables in -ц palatalize ц to ч before -ев-: зец → зечеви (rabbits), стриц → стричеви (uncles). In contrast, nouns with fleeting а ending in -ц typically take the short plural in -и without palatalization: ланац → ланци (chains), јарац → јарци (goats). Foreign loanwords also keep ц: виц → вицеви (jokes).
  - Note: A few very frequent monosyllabic nouns take the short plural -и instead of -ови/-еви: дан → дани (days), зуб → зуби (teeth), прст → прсти (fingers), гост → гости (guests), сат → сати (hours).
• Watch for fleeting а and sound changes before -и: момак → момци (young men), ученик → ученици (pupils). Note that sibilarization (к, г, х → ц, з, с) occurs before the short ending -и, but never before the long plural infix -ов- (e.g., вукови, not *вуцови).
• Masculine nouns ending in -а (such as колега, судија, тата) decline like feminine a-stems and take -е in the plural: колеге (colleagues), судије (judges), тате (dads).

2. Feminine Nouns
• Feminine nouns ending in -а replace singular -а with -е: жена → жене (women), столица → столице (chairs), књига → књиге (books).
• Feminine nouns ending in a consonant (i-stems) take -и in the nominative plural: ствар → ствари (things), ноћ → ноћи (nights), реч → речи (words).

3. Neuter Nouns (ending in -о or -е)
• Neuter nouns swap their singular ending for -а: село → села (villages), писмо → писма (letters), поље → поља (fields).
• Certain neuter nouns ending in -е expand their stem with -ен- before adding the plural ending: име → имена (names), време → времена (times).
• Watch out: A neuter plural ending in -а looks identical to a feminine singular noun, but it is plural and agrees with plural verbs and adjectives: Села су лепа (Villages are beautiful), not *Села је лепа.

Syntax & Quantity Warning:
Nominative plural forms are used whenever a plural subject is unquantified or modified by demonstratives/determiners like сви (all) or ови (these): Ови студенти вредно уче (These students study hard). However, counting and quantification trigger different case forms: nouns use the count form (paucal) after 2, 3, 4 (e.g., два студента), and the genitive plural after 5 and up (e.g., пет студената) or after adverbs of quantity such as много, мало, неколико, and доста (e.g., много студената).