-ost / -nost

Abstract Nouns in -ost and -nost

Level 5

The suffix -ost is the most productive way to create abstract nouns from adjectives in Czech. Despite ending in a consonant, these nouns are strictly feminine.

How It Works

1. Formation and Phonology
For modern and productive words, simply drop the adjective ending and add -ost (e.g., zaujatý → zaujatost). In older, established derivations, you might see vowel shortening or root alternations (e.g., bílý [white] → bělost; líný [lazy] → lenost). Note that velikost (size) is derived directly from the parallel adjective veliký, not velký.

2. Meaning and Lexicalization
While they primarily denote abstract qualities (rychlost = speed), many have lexicalized into concrete, countable entities. For example, místnost (room), domácnost (household), písemnost (document), or sladkost (a piece of candy).

3. Contrast with Other Suffixes
Do not confuse -ost with -ství / -ctví. The suffix -ost attaches to adjectives to form feminine qualities, whereas -ství attaches to both nouns (e.g., přítel → přátelství) and adjectives (e.g., bohatý → bohatství) to form neuter states or institutions.

4. Grammatical Gender and Declension
A common beginner oversimplification states that consonant-ending nouns are masculine. The -ost suffix proves this false, accounting for thousands of feminine nouns. Always use feminine agreement: ta nová možnost (that new possibility), never *ten nový možnost. However, be careful with non-derived base nouns that simply happen to end in the letters -ost, such as most (bridge) or host (guest). In these words, -ost is part of the root, not a suffix, and they are regular masculine nouns. These derived feminine nouns decline according to the kost paradigm. Crucially, the accusative is identical to the nominative in both the singular and plural (e.g., Mám novou možnost, Vidím dvě možnosti). Other key endings include -i in the genitive, dative, vocative, and locative singular, as well as the nominative and vocative plural (e.g., bez možnosti, k možnosti, radosti moje!, o možnosti, dvě možnosti), -í in the instrumental singular (e.g., s možností) and genitive plural (e.g., pět možností), -em in the dative plural (e.g., k možnostem), -ech in the locative plural (e.g., o možnostech), and -mi in the instrumental plural (e.g., s těmi možnostmi).

Examples (5)

  1. Na dálnici platí nejvyšší povolená rychlost 130 km/h.

    The maximum permitted speed on the highway is 130 km/h.

    Word by Word: On highway applies highest permitted speed 130 km/h.

    Derived from the adjective 'rychlý' (fast). It denotes the abstract quality of speed.

  2. Dostupnost služby závisí na vašem tarifu.

    The availability of the service depends on your plan.

    Word by Word: Availability of-service depends on your plan.

    Derived from 'dostupný' (available). Notice how the '-n-' is part of the adjective stem, creating the illusion of a '-nost' suffix.

  3. Udělalo mi obrovskou radost, že jsi přišel.

    It gave me enormous joy that you came.

    Word by Word: It-made to-me enormous joy, that you came.

    Derived from 'rád' (glad). 'Radost' is one of the most common abstract nouns in Czech.

  4. Tato místnost je určena pouze pro zaměstnance.

    This room is intended only for employees.

    Word by Word: This room is intended only for employees.

    Derived from 'místní' (local). This is a prime example of an abstract suffix lexicalizing into a concrete, physical noun (a room).

  5. Jeho zaujatost proti novému projektu byla zjevná.

    His bias against the new project was obvious.

    Word by Word: His bias against new project was obvious.

    Derived from the passive participle 'zaujatý' (biased). The stem remains unchanged in modern derivations.

Common Mistakes

  • Assuming nouns ending in -ost are masculine inanimate because they end in a consonant.

    Ten nový možnost je velmi zajímavý.
    Ta nová možnost je velmi zajímavá.

    All nouns formed with the suffix -ost are strictly feminine. You must use feminine adjective and pronoun agreement, despite the consonant ending.

  • Applying masculine instrumental endings instead of feminine ones.

    Přijal tu zprávu s velkým radostem.
    Přijal tu zprávu s velkou radostí.

    Because these are feminine nouns of the kost paradigm, their instrumental singular ending is -í, not the masculine -em. Adjectives must also take the feminine instrumental ending (-ou).

  • Assuming all words ending in the letters '-ost' are feminine, even when '-ost' is part of the root.

    Šli jsme přes tu novou most.
    Šli jsme přes ten nový most.

    Words like most (bridge) or host (guest) are not abstract nouns derived with the suffix -ost. The letters '-ost' are just part of their root. Therefore, they are regular masculine nouns and take masculine agreement.

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-ost / -nostLevel 5Abstract Nouns in -ost and -nost

Learn This First

To understand how abstract nouns are formed with -ost and -nost, learners must first be familiar with the adjectives and participles that serve as their base. Additionally, since these derived nouns are always feminine, knowledge of feminine noun categories is required for their correct usage and declension.

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