-kas/-käs

Rich in Something (-kas/-käs)

Level 4

The suffix -kas/-käs turns root words (nouns, verbs, and adjectives) into adjectives or nouns. It doesn't just mean 'having' something, but emphasizes an abundance or intensity of that thing (e.g., voima 'power' → voimakas 'powerful').

How It Works

The -kas/-käs suffix is a powerful tool for building vocabulary. Here is how it works:

1. Meaning and Nuance:
It indicates that the subject is characterized by a high degree of the root word. For example, voima (power) → voimakas (powerful).

2. Nouns Denoting Persons:
In addition to adjectives, this suffix is frequently used to form nouns denoting persons or actors from verbs or other nouns. Examples include asia (matter/business) → asiakas (customer), and asua (to reside) → asukas (resident).

3. Moderative Meaning (Rare):
Occasionally, when attached to an adjective, the suffix can give a moderative ('-ish' or 'somewhat') meaning (e.g., kuiva → kuivakas, dryish). However, this is rare in standard Finnish; the suffix -hko/-hkö is the standard and productive way to express this meaning.

4. Morphological Changes:

  • Base Stem and Gradation: Many derivatives resemble the base noun’s inflectional stem: taito → taidon → taidokas. This does not mean every base is weak-grade: inverse-gradation taide → taiteen has strong t, retained in taiteikas, and many bases have no gradation at all. Learn the established derivative rather than attaching the suffix mechanically to every genitive.
  • The -(i)kas/-(i)käs Variant: Some derivatives have an i before the suffix, often resembling the noun’s plural stem. The notation -(i)kas/-(i)käs helps you remember that variation; the derivative itself is not grammatically plural. Examples: kukka → kukikas (flowery), kuva → kuvikas (patterned), taide → taiteikas (artistic), maine → maineikas (renowned).
  • Consonant Stems: For nouns ending in a consonant, the suffix is added to the inflectional (vowel) stem. Example: mies (man) → miehe- + -käs = miehekäs (manly).
  • Vowel Harmony: Use -kas for back vowels (a, o, u) and -käs for front vowels (ä, ö, y). Words containing only neutral vowels (e, i) take the front vowel suffix -käs (e.g., mieli → mielekäs).

5. Declension (The 'vieras' Type):
This is an important part to become proficient in. The suffix follows nominal stem type 41. In the singular vowel stem, -kas/-käs → -kkaa-/-kkää-: the final s disappears, k strengthens to kk, and a/ä lengthens. Thus tehokas → tehokkaa- + -n → tehokkaan. Note that nouns formed with this suffix, such as asiakas (customer), decline exactly the same way as adjectives like tehokas:

  • Nominative: tehokas (effective)
  • Genitive: tehokkaan
  • Partitive: tehokasta (Note: The -s remains here!)
  • Illative: tehokkaaseen
  • Plural Nominative: tehokkaat
  • Plural Partitive: tehokkaita (Note: The stem changes to -kkai- before the ending)

6. Adverb Formation:
To form manner adverbs, add -sti to the long-vowel stem, producing -kkaasti/-kkäästi. For example, tehokas (effective) becomes tehokkaasti (effectively).

Examples (5)

  1. Hän on erittäin voimakas ja taidokas urheilija.

    He/she is a very strong and skillful athlete.

    Word by Word: He/she is very powerful and skillful athlete.

    Here, 'voimakas' (from voima) and 'taidokas' (from taito) describe high levels of strength and skill.

  2. Tämä vanha sormus on todella arvokas.

    This old ring is really valuable.

    Word by Word: This old ring is really value-rich.

    'Arvokas' comes from 'arvo' (value). It is one of the most common adjectives using this suffix.

  3. Älä ole niin itsekäs, vaan ajattele muitakin!

    Don't be so selfish; think of others too!

    Word by Word: Don't be so self-rich, but think others-also!

    'Itsekäs' (from itse - self) is the standard Finnish word for 'selfish'.

  4. Meillä oli oikein ratkiriemukas ilta.

    We had a truly hilarious/joyful evening.

    Word by Word: We had truly joy-rich evening.

    'Riemukas' comes from 'riemu' (joy/jubilation).

  5. Tunnen tämän tehokkaan menetelmän.

    I know this effective method.

    Word by Word: I know this effective-of method-of.

    This shows the genitive form: 'tehokas' becomes 'tehokkaan'.

Common Mistakes

  • Assuming the suffix always attaches to the singular stem.

    taidekas
    taiteikas

    For nouns ending in -e, the suffix attaches to the plural stem containing an -i- (taitei- + -kas = taiteikas).

  • Declining the adjective like a simple vowel stem.

    voimakasan
    voimakkaan

    Adjectives ending in -kas follow the 'vieras' declension pattern, where the whole ending -kas becomes -kkaa- in the vowel stem, followed by genitive -n.

  • Doubling the -k- in the partitive singular.

    voimakkasta
    voimakasta

    The partitive singular is an exception in the declension; it keeps the single -k- and the -s.

How It Connects

Tap a pattern to see what it builds on and what it leads to.

-kas/-käsLevel 4Rich in Something (-kas/-käs)

Learn This First

To use the -kas/-käs suffix, you need to understand how vowel harmony determines the suffix form and how the 'k' in the suffix doubles to 'kk' (consonant gradation) when the word is declined in different cases.

Words in This Pattern

-kas-käs