Learn Hardcore Finnish: Otan sateenvarjon mukaan, etten kastu matkalla pysäkille. - I take an umbrella with me so that I don’t get wet on the way to the stop.

Finnish usually drops the subject pronoun because the verb ending already shows the person. Otan = I take / I’ll take (1st person singular). You can add minä for emphasis or contrast (e.g., Minä otan sateenvarjon, mutta sinä et ota).

What tense is otan? Is it “I take” or “I will take”?

It’s the present tense, but Finnish present often covers near-future plans too. So Otan sateenvarjon mukaan can naturally mean I’m taking / I’ll take an umbrella with me depending on context.

Why does sateenvarjo become sateenvarjon?

Because the umbrella is the object and here it’s treated as a total object (something you take as a whole). In Finnish, that often shows up as -n (genitive/accusative-like form) in the singular:

sateenvarjo (basic form) → sateenvarjon (object form here)

When would it be sateenvarjoa instead?

Sateenvarjoa is partitive, used when the action is incomplete/ongoing, or the amount is “some/indefinite,” or in negatives. For example:

En ota sateenvarjoa mukaan. = I’m not taking an umbrella with me.
Otan sateenvarjoa esiin. (context-dependent, could imply “I’m getting at the umbrella / handling it,” not taking it as a complete “item to bring along”)

What exactly does mukaan mean, and why is it used with sateenvarjon?

mukaan means along (with me), with me, to take along. It commonly goes with a noun in the genitive (-n):

sateenvarjon mukaan = (take) the umbrella along
It’s a set pattern: [something]-n mukaan.

What is etten, and how is it formed?

etten is a fused form meaning so that I don’t / in order that I don’t. It comes from että + the negative verb en:

että + en → etten
It introduces a subordinate clause expressing purpose (especially in the negative).

Why is it kastu and not kastun?

Because in Finnish negative clauses use a special pattern: the negative auxiliary carries the person (en, et, ei, etc.), and the main verb appears in the connegative form (no personal ending).
So:

positive: kastun = I get wet
negative: en kastu = I don’t get wet
Inside this sentence, etten kastu = so that I don’t get wet.

Could it be ettei instead of etten?

Yes, but the meaning and grammar shift slightly:

etten explicitly matches I (1st person): so that I don’t…
ettei is more general: so that (someone) doesn’t… / so that it won’t…
In many contexts, people still use ettei even when the subject is “I,” but etten is the clearest match here.

Could I also say jotta en kastu or jotten kastu?

Yes. These are common alternatives for purpose:

jotta en kastu = so that I don’t get wet (very common, transparent)
jotten kastu = a contracted form like etten, built from jotta + en
All are understandable; etten kastu is a neat compact option.

Why is there a comma before etten?

Because Finnish typically separates the main clause and a subordinate clause with a comma. Here:

Main clause: Otan sateenvarjon mukaan
Purpose clause: etten kastu matkalla pysäkille

What case is matkalla, and what does it add?

matkalla is the adessive case (-lla/-llä). With matka it commonly means on the way / during the journey:

matkalla = on the way, en route
So etten kastu matkalla pysäkille = so that I don’t get wet on the way to the stop.

Why is it pysäkille and not pysäkillä?

Because pysäkille is allative (-lle), meaning to/toward the stop (destination).

pysäkille = to the stop
pysäkillä (adessive) = at the stop
So this sentence focuses on not getting wet while going to the stop, not while waiting at it.