siksi / siis / sen takia
Therefore Words
Finnish uses siksi, siis, and sen takia to express 'therefore' or 'so'. They connect a cause to its effect.
How It Works
These connectors are essential for building complex sentences at an intermediate level.
- siksi: A standard adverb meaning 'that is why' or 'for that reason'. It is the standard response to the question miksi. In formal writing, when linking two main clauses, it should follow a semicolon or a coordinating conjunction (e.g., ja siksi).
- siis: A versatile particle meaning 'so' or 'consequently'. While eli is used for restating (A = B), siis is used for concluding or self-correcting (A → B). It can be placed at the start of a sentence or right after the verb.
- sen takia: A phrase meaning 'because of that'. It consists of the genitive form of se (it/that) and a postposition. It is largely interchangeable with siksi in neutral contexts.
Directionality:
When used alone, siksi and sen takia refer backward to a reason already mentioned. To point forward to a reason about to be explained, you must use the structures siksi, että or sen takia, että (always with a comma).
Examples (6)
- Hän unohti avaimet, ja siksi hän ei päässyt sisään.
He forgot the keys, and for that reason, he couldn't get in.
Word by Word: He forgot keys, and for-that-reason he not get inside.
In formal writing, 'siksi' is often preceded by a conjunction like 'ja' (and) or a semicolon when linking two main clauses.
- Ulkona sataa, sen takia meidän täytyy peruuttaa retki.
It is raining outside; for that reason, we have to cancel the trip.
Word by Word: Outside rains, that because-of we must cancel trip.
This uses 'sen takia' to link the weather to the necessary action. It is interchangeable with 'siksi' here.
- Olen myöhässä, olen siis menettänyt vuoroni.
I am late; I have, therefore, lost my turn.
Word by Word: I-am late, I-am therefore lost my-turn.
Here 'siis' indicates a logical conclusion (A → B) rather than just a restatement.
- Hän on sairas siksi, että hänellä on kuumetta.
He is sick for the reason that he has a fever.
Word by Word: He is sick for-that-reason, that he-on fever.
When 'siksi' points forward to a reason, it must be followed by a comma and the word että.
- Miksi sinä teit niin? — Siksi.
Why did you do that? — Just because.
Word by Word: Why you did so? — For-that-reason.
'Siksi' is the standard one-word answer to the question miksi.
- Siis etkö sinä haluakaan lähteä?
So, you don't want to go after all?
Word by Word: So not-question you want-either to-go?
In spoken Finnish, 'siis' is often used at the start of a question to clarify or conclude a situation.
Common Mistakes
Using 'siksi koska' together.
En tullut siksi koska satoi.En tullut, koska satoi.Using both 'siksi' and 'koska' is redundant. Use koska (because) alone, or use the structure 'siksi, että' (for the reason that).
Using 'siis' where 'eli' (in other words) is meant.
Different MeaningTämä on koira, siis eläin.Tämä on koira, eli eläin.'Tämä on koira, siis eläin' is a good sentence: 'siis' means 'so' or 'therefore' and draws a conclusion. Use 'eli' ('in other words') for a direct synonym or a definition.
Omitting the comma before 'että' in the 'siksi, että' structure.
Teen sen siksi että haluan.Teen sen siksi, että haluan.In the 'siksi, että' structure, a comma is mandatory before the subordinate clause starting with 'että'.
How It Connects
Learn This First
To understand 'therefore' words, you need to be familiar with basic demonstrative pronouns (specifically 'se'), as these words literally mean 'for that' or 'because of that'. You should also understand how to ask 'why' (miksi) and have experience joining simple sentences with basic conjunctions.
- tämä / tuo / seThis, That, It
The words 'siksi' and 'sen takia' are derived from the demonstrative pronoun 'se' (it/that), which is used to refer back to a previously mentioned reason.
Level 1 - miksiWhy (Miksi)
Understanding the question word for 'why' is functionally necessary to understand the corresponding 'therefore' or 'that's why' responses.
Level 1 - ja / mutta / taiBasic Conjunctions
Basic conjunctions provide the foundation for understanding how to link two independent clauses together before moving to logical connectors like 'therefore'.
Level 1
Related Patterns
- koskaBecause (Koska)
While 'siksi' introduces a result, 'koska' introduces the reason (because).
Level 2 - ettäThat-Clause (Että)
'Siksi' is often followed by an 'että' clause to explain a specific reason: 'siksi, että...' (due to the fact that...).
Level 2 - Postpositions Follow the Genitive
'Sen takia' is a postpositional phrase where 'se' must be in the genitive case.
Level 2 - et / ku / mut / sitSpoken Linking Words
'Siis' is a very common filler and connector in spoken Finnish, similar to these reduced forms.
Level 2
Words in This Pattern
Practice siksi / siis / sen takia in Bubblegum
Poppy, your AI tutor, writes Finnish lessons at your level. Tap any grammar point in a lesson to see its full explanation.
