The noun cases are typically referred to by number, and learned by means of the question to which they are the answer. When learning a new word, children recite the cases using a set of example phrases, shown as follows:
1. kdo/co? (who/what?) nominative
2. bez koho/čeho? (without whom/what?) genitive
3. komu/čemu? (to whom/what?) dative
4. vidím koho/co? (I see whom/what?) accusative
5. volám (I call) vocative
6. o kom/čem? (about whom/what?) locative
7. s kým/čím? (with whom/what?) instrumental
The case used depends on a number of variables, and for foreigners can be very confusing.
The simplest of the rules governing noun declension is the use of prepositions (předložky). Excepting expressions and common phrases, each preposition is matched with a certain noun declension case depending on use. The following are basic examples of common prepositions and their corresponding noun cases (note: these examples represent only one circumstance. Often each preposition can be used with two or more noun cases depending on the sentence).
* Genitive: během (during), podle/dle (according to/along), vedle (beside), kolem (around), okolo (around), do (into), od(e) (away from), z(e) (out of/from), bez(e) (without), místo (instead of).
* Dative: k(e) (towards), proti (against), díky (thanks to), naproti (opposite).
* Accusative: skrz(e) (through), pro (for), na (to/for).
* Locative/Prepositional: o (around, about), na (on), při (into, in, around), v (in), po (after, around).
* Instrumental: za (behind), před (in front of), mezi (between), pod(e) (below), s(e) (with), nad(e) (above).
Many of the above prepositions are used in different circumstances. For instance, when motion or a change of position is expressed, prepositions like nad, mezi, na, pod, etc. are used with the accusative case.
The second factor affecting noun declension is the verb used. In Czech grammar, the accusative case serves as the direct object, and the dative case serves as the indirect object. Some verbs require the genitive case to be used. For example, the verb "zeptat se" (to ask) requires that the person being asked the question be in the genitive case (Zeptat se koho/čeho), and that the thing being asked about follow the preposition "na" and be in the accusative case (Zeptat se koho/čeho na koho/co).
The third factor affecting noun declension is number. The Czech language has a very complex counting system, explained as follows with the example masculine animate noun muž (man):
* For the number one, the singular number is of course used: jeden muž.
* For the numbers 2, 3, and 4, any case may be used, depending on the function of the noun in the sentence: dva muži (nominative). "Vidím dva muže" (accusative).
* For all numbers from 5 to infinity, the genitive plural is used when the noun would normally be in the nominative, accusative or vocative case: pět mužů. "Pět mužů je tam." Five men are over there. "Vidím pět mužů." I see five men. For other cases, however, the noun is not placed in the genitive. "Nad pěti muži." Above the five men (instrumental).
That's in colloquial use. In literary use, there is an additional rule: the above system is based only on the last word of the number. Thus a number like 101 uses the singular (sto jeden muž) and 102 uses the ordinary plural (sto dva muži). For numbers which can be read in two ways, such as 21, the grammar may depend on which one is chosen (dvacet jeden muž or jednadvacet mužů).
Numbers also have declension patterns in Czech. The number two, for instance, declines as follows:
Locative (o) dvou
The numbers are singular (jednotné číslo), plural (množné číslo), and remains of dual. The dual number is used for only several parts of the human body, of which each person has two: hands, shoulders, eyes, ears, knees, legs, breasts. In all but two of the above body parts (eyes and ears) the dual number is only vestigial and affects very few aspects of declension (mostly the genitive and prepositional cases).
GenderThe three genders are masculine, feminine, and neuter, with masculine further subdivided into animate and inanimate. Words for individuals with biological gender usually have the corresponding grammatical gender, with only a few exceptions; similarly, among the masculine nouns, the distinction between animate and inanimate also follows meaning. Other words have arbitrary grammatical genders. Thus, for instance, pes (dog) is masculine animate, stůl (table) is masculine inanimate, kočka (cat) and židle (chair) are feminine, and morče (guinea-pig) and světlo (light) are neuter.