pět a více

For numbers 5 and higher (with specific exceptions for compound numbers ending in 1–4), the genitive plural noun rule is mandatory in all registers of Czech, though the verb agreement differs. In Standard Czech, the neuter singular verb is required, but in informal, colloquial speech, you will frequently hear plural verbs. Think of "pět studentů" literally as "a five of students."

1. The Genitive Plural Rule
Instead of the normal plural, nouns take the genitive plural. For masculine nouns, this usually means adding -ů (studentů). For hard-stem feminine and neuter nouns, it often means dropping the final vowel to leave a bare stem (koruna → korun). If this leaves a hard-to-pronounce consonant cluster at the end, an 'e' (vkladné e) is often inserted (okno → oken). For soft-stem feminine and neuter nouns, the ending is often -í (růže → růží, moře → moří), but many take a zero ending (bare stem), such as feminine nouns ending in -ice (ulice → ulic) and neuter nouns ending in -iště (letiště → letišť). Finally, watch out for three extremely common irregular genitive plurals: člověk (person) becomes lidí (pět lidí - five people), rok (year) becomes let (pět let - five years), and dítě (child) becomes dětí (pět dětí - five children).

2. The Neuter Verb Rule
Because the number itself acts syntactically as a singular neuter subject, the verb must agree with it in Standard Czech. In the present tense, use the third-person singular (Pět studentů je tady. - Five students are here, NOT jsou). In the past tense, this means using the -lo ending: Pět studentů přišlo. (Five students came.) Note that in everyday spoken Czech, people often use the plural verb instead (e.g., Pět studentů přišli.), but remember this is considered a grammatical error in standard written Czech and formal exams.

3. The "Two Regimes" (Crucial Exception)
This rule applies in the nominative, accusative, and vocative cases. If the phrase is in any other case (Genitive, Dative, Locative, Instrumental)—whether governed by a preposition or a verb—the "genitive after five" rule vanishes. The noun takes the case dictated by the preposition or verb, and the number agrees with the noun in case (though unlike true adjectives, numerals 5–99 do not change for gender). For numbers up to 99, such as 5–19, round tens, numbers ending in 5–9, and single-word inverted forms (e.g., dvaadvacet), the declension is simple: they take the ending -i in all oblique cases (e.g., pět becomes pěti for all genders). For example, with Instrumental after s and se: s pěti muži (with five men), NOT s pěti mužů, or with a verb taking the dative: pomáhat pěti studentům (to help five students). For compound numbers ending in 1–4 (like 21 or 22), you have two choices in oblique cases: decline both words (e.g., s dvaceti dvěma studenty) or use the easier inverted form which takes the simple -i (e.g., s dvaadvaceti studenty). For higher numbers, there is a special rule. Nouns like milion (1,000,000) and miliarda (1,000,000,000) decline like standard nouns in oblique cases, but the counted noun remains in the genitive plural (e.g., s milionem korun, NOT s milionem korunami). For sto (100) and tisíc (1,000), both patterns are acceptable: you can keep the genitive plural (se stem lidí) or decline both words (se sto lidmi).

4. Compound Numerals (21, 22, 101, etc.)
For numbers above 20, the grammar depends on how you say them. If you read them as separate words ending in 1–4, the last digit dictates the grammar: numbers ending in 1 require the nominative singular (dvacet jeden student), while numbers ending in 2, 3, or 4 require the nominative plural (dvacet dva studenti). In informal spoken Czech, you might hear people apply the genitive plural rule to separate-word numbers ending in 1 by freezing the word 'jeden' into 'jedna' (e.g., dvacet jedna studentů), but this is considered incorrect in standard written Czech. However, if you use the single-word inverted form (e.g., jednadvacet, dvaadvacet), it acts like a number 5 or higher and strictly takes the genitive plural: jednadvacet studentů.