-sti

Adverbs with -sti

Level 2

Adjective + -sti = Adverb (e.g., 'slow' → 'slowly').

How It Works

The -sti suffix is the most common way to create adverbs of manner in Finnish. It answers the question miten? (how?) or millä tavalla? (in what way?).

1. Formation
The suffix is attached to the inflectional stem (the same stem used for the genitive case). This requires applying consonant gradation:

  • helppo (easy) → helpo- + -sti = helposti (easily)
  • hidas (slow) → hitaa- + -sti = hitaasti (slowly)
  • kaunis (beautiful) → kaunii- + -sti = kauniisti (beautifully)

2. Special Stem Changes
Adjectives ending in -nen change to -se- before the suffix:

  • iloinen (happy) → iloisesti (happily)
  • tavallinen (usual) → tavallisesti (usually)

3. Usage and Comparison
Unlike adjectives, adverbs do not agree with the noun they modify; they remain invariant. However, they can be compared using comparative forms (e.g., nopeasti → nopeammin) and superlative forms (e.g., nopeimmin).

4. Exceptions
A few very common adjectives do not use -sti. Instead, they use the instructive ending -in:

  • hyvä (good) → hyvin (well)
  • oikea (correct) → oikein (correctly)
  • väärä (wrong) → väärin (wrongly)

Note: oikeasti (really/actually) exists but has a different meaning than oikein (correctly).

Examples (5)

  1. Hän ajaa autoa varovasti.

    He/she drives the car carefully.

    Word by Word: He/she drives car carefully.

    The adjective 'varovainen' (careful) becomes 'varovasti' (carefully).

  2. Lapset leikkivät iloisesti pihalla.

    The children are playing happily in the yard.

    Word by Word: Children play happily yard-on.

    The -nen adjective 'iloinen' changes its stem to 'iloise-' before adding -sti.

  3. Ole kiltti ja puhu hitaasti.

    Please be kind and speak slowly.

    Word by Word: Be kind and speak slowly.

    The adjective 'hidas' (slow) uses its strong stem 'hitaa-' to form 'hitaasti'.

  4. Minä ymmärrän tämän helposti.

    I understand this easily.

    Word by Word: I understand this easily.

    The adjective 'helppo' (easy) undergoes consonant gradation (pp -> p) to become 'helposti'.

  5. Lintu laulaa kauniisti.

    The bird sings beautifully.

    Word by Word: Bird sings beautifully.

    The adjective 'kaunis' (beautiful) uses the stem 'kaunii-' to form 'kauniisti'.

Common Mistakes

  • Using 'oikein' when you mean 'really'.

    Different MeaningHän puhuu oikein.
    Hän puhuu oikeasti.

    'Hän puhuu oikein' is a good sentence, but it means 'He speaks correctly.' 'Oikeasti' means 'really' or 'in reality'. If you mean that he really speaks, use 'oikeasti'.

  • Using the wrong stem for adjectives with consonant gradation.

    Puhu hitasti.
    Puhu hitaasti.

    The suffix -sti must be added to the inflectional stem. For 'hidas', the stem is 'hitaa-'. This is the same stem used in the genitive case.

  • Over-regularizing 'hyvä' to 'hyvästi'.

    Minä voin hyvästi.
    Minä voin hyvin.

    'Hyvästi' is a specific word meaning 'farewell'. To say 'well' (the adverb of 'good'), you must use the irregular form 'hyvin'.

How It Connects

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-stiLevel 2Adverbs with -sti

Learn This First

To form adverbs with -sti, you need to know how to find the inflectional stem of an adjective (usually the same stem used for the genitive case) and how consonant gradation affects that stem, as -sti always attaches to the strong grade.

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-sti