koska

Because (Koska)

Level 2

Koska is the most common way to say 'because' in Finnish. It links a reason to an action. It can also mean 'when' in questions, similar to milloin.

How It Works

1. Expressing Cause ('Because')
Koska is a subordinating conjunction. It connects a main clause to a dependent clause that provides the reason. Unlike the English 'because', Finnish grammar requires a comma to separate these clauses.

  • Minä syön, koska minulla on nälkä. (I eat because I am hungry.)

2. Sentence Position and 'Sillä'
The koska-clause can come after the main clause or at the very beginning of the sentence for emphasis. If it starts the sentence, the comma follows the entire subordinate clause. Note that while sillä also means 'because', it is a coordinating conjunction and can never start a sentence.

  • Koska satoi, jäimme kotiin. (Because it rained, we stayed home.)

3. 'Koska' as a Question Word
In questions, koska means 'when'. While milloin is often preferred in formal writing or in subordinate clauses to avoid ambiguity with 'because', koska is very common in everyday speech.

  • Koska juna lähtee? (When does the train leave?)

4. Spoken Finnish Variations
In spoken Finnish, koska is frequently replaced by the word ku (short for kun).

Examples (4)

  1. Lähden kotiin, koska olen väsynyt.

    I am going home because I am tired.

    Word by Word: I-go home, because I-am tired.

    A standard sentence where 'koska' introduces the reason. Note the mandatory comma.

  2. Koska ulkona satoi, otin sateenvarjon.

    Because it was raining outside, I took an umbrella.

    Word by Word: Because outside rained, I-took umbrella.

    When the 'koska' clause starts the sentence, the comma is placed after the clause ends.

  3. Koska sinä tulet kotiin?

    When are you coming home?

    Word by Word: When you come home?

    Here 'koska' acts as a question word meaning 'when', synonymous with 'milloin'.

  4. En ostanut sitä, koska se oli kallis.

    I didn't buy it because it was expensive.

    Word by Word: Not I-bought it, because it was expensive.

    Using 'koska' to explain the reason for a negative action.

Common Mistakes

  • Omitting the comma before 'koska'.

    Menen nukkumaan koska olen väsynyt.
    Menen nukkumaan, koska olen väsynyt.

    In Finnish, subordinate clauses starting with 'koska' must be separated from the main clause by a comma.

  • Syön, kun olen nälkäinen is fine, but it means "I eat when I am hungry".

    Different MeaningSyön, kun olen nälkäinen.
    Syön, koska olen nälkäinen.

    Kun mainly gives the time ("when"); koska gives the reason ("because"). Use koska when you explain why you eat.

How It Connects

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

koskaLevel 2Because (Koska)

Learn This First

To use 'koska' (because), you need to be able to form two complete clauses and understand that this word specifically answers the question 'miksi' (why). It functions as a bridge between a result and its reason.

Words in This Pattern

koskakoska