Learn Hardcore Finnish: Odotan junaa asemalla, koska bussi on myöhässä. - I am waiting for the train at the station because the bus is late.

Because odottaa (to wait for) normally takes a partitive object: odottaa jotakin.
So odotan junaa is the standard way to say I’m waiting for the train. This is true even if you mean a specific train; it’s just how the verb typically governs its object in Finnish.

What case is asemalla, and why is it used here?

Asemalla is the adessive case (-lla/-llä), which often means on/at a place.
So asemalla = at the station (location “at” a place, not inside it).

Could it be asemassa instead of asemalla? What’s the difference?

Yes, but it changes the nuance:

asemalla (adessive) = at the station (the station area/location)
asemassa (inessive) = in the station (inside the building, more “indoors”)

In everyday Finnish, asemalla is very common for at the station in the general sense.

Why does Finnish use present tense (odotan) when English uses I’m waiting?

Finnish doesn’t have a separate grammatical form like the English present continuous. The simple present often covers “right now” actions:

Odotan junaa. can mean I wait for the train or I’m waiting for the train, depending on context.

How is odotan formed from odottaa?

Odottaa is the infinitive (to wait). The present tense forms include:

(minä) odotan = I wait / I’m waiting
hän odottaa = he/she waits

Notice the change tt → t in odotan. That’s a common Finnish pattern (consonant gradation) in many verbs.

Why is there a comma before koska?

In Finnish, you normally put a comma before a subordinate clause introduced by words like koska (because):

Odotan junaa asemalla, koska bussi on myöhässä.

This is more strict than in English, where commas with because are optional and meaning-dependent.

Can the word order be changed, like starting with koska?

Yes. You can front the reason clause:

Koska bussi on myöhässä, odotan junaa asemalla.

Both are correct. The first version (original) feels neutral; the second puts more focus on the reason first.

Why is it bussi on myöhässä and not something like “late” as a normal adjective?

Finnish commonly expresses to be late with the phrase:

olla myöhässä = to be late

Here myöhässä is the inessive form (-ssa/-ssä) and literally suggests being in a state of lateness. It’s an idiomatic, fixed-feeling expression.

Is on the only option here? What is its role?

On is the 3rd person singular present form of olla (to be):

bussi on myöhässä = the bus is late

So on is just the normal present-tense copula is.

Where are the and a? How do I know if it’s a train or the train?

Finnish has no articles, so juna/junaa can be a train or the train. The intended meaning comes from context:

If you’re at a station and there’s an expected train, odotan junaa will often be understood as I’m waiting for the (expected) train.
If it’s more general, it can be a train.