Learn Hardcore Finnish: Seuraan kanavaa, jossa opettaja selittää suomea hitaasti. - I follow a channel where the teacher explains Finnish slowly.

Seuraan comes from the verb seurata (to follow).
The ending -n marks 1st person singular, present tense → “I follow”.
You can say Minä seuraan kanavaa, but minä is only needed for emphasis or contrast (e.g. Minä seuraan, mutta hän ei seuraa – I follow, but he/she doesn’t).

So Seuraan kanavaa is automatically understood as “I follow a channel.”

Why is it kanavaa and not kanava or kanavan?

Kanavaa is the partitive singular of kanava (channel).

kanava = nominative (basic dictionary form)
kanavan = genitive / total object form (often used when the object is seen as complete)
kanavaa = partitive (often used for ongoing, incomplete, or “some/any” type objects)

The verb seurata (to follow) typically takes its object in the partitive:

Seuraan kanavaa. = I follow (some/a) channel.
Seuraan häntä. = I follow him/her. (häntä is also partitive)

Using kanavaa here reflects that you are following it over time, not completing some one‑time action on the whole channel.
A form like Seuraan kanavan would sound very odd in this meaning.

What exactly does jossa mean, and how is it related to joka?

Jossa is a relative pronoun meaning roughly “where” or “in which.”

Its base form is joka = which / that / who.
jossa is inessive singular of joka (the -ssa ending = “in”).

You can think of the sentence like this:

Seuraan kanavaa. Kanavassa opettaja selittää suomea hitaasti.
I follow a channel. In the channel, the teacher explains Finnish slowly.

When you combine these, kanavassa is replaced by jossa:

Seuraan kanavaa, jossa opettaja selittää suomea hitaasti.
I follow a channel where (in which) the teacher explains Finnish slowly.

So jossa = “in which / where (in it)”, referring back to kanavaa.

Why is there a comma before jossa?

In standard Finnish punctuation, you usually put a comma between a main clause and a subordinate clause introduced by words like jossa, että, koska, kun, vaikka etc.

Main clause: Seuraan kanavaa
Subordinate (relative) clause: jossa opettaja selittää suomea hitaasti

So you write:

Seuraan kanavaa, jossa opettaja selittää suomea hitaasti.

The comma is not optional here in normal written Finnish.

Why is opettaja in that plain form (no ending)?

Opettaja (teacher) is in the nominative singular, because it is the subject of the subordinate clause.

In jossa opettaja selittää suomea hitaasti:

opettaja = the one doing the explaining → the subject
selittää = the verb
suomea = the object

Subjects in Finnish are usually in the nominative (basic) form, unless something special is going on (like a passive or certain existential constructions). Here it’s just a normal subject → opettaja.

What form is selittää here, and why does it look like the dictionary form?

Selittää is both:

the dictionary form (1st infinitive), and
the 3rd person singular present tense: hän selittää = he/she explains

For this verb:

infinitive: selittää
3rd person singular: hän selittää

They just happen to look the same in spelling. You know it’s finite (a real verb in a clause) here because it follows a subject:

opettaja selittää = the teacher explains (present tense statement)

So in the sentence, selittää is “explains”, not an infinitive like to explain.

Why is suomea (partitive) used instead of suomi or suomen?

Suomea is the partitive singular of suomi (Finnish, the Finnish language).

For languages as objects of verbs like puhua (to speak), opiskella (to study), opettaa (to teach), selittää (to explain), Finnish very often uses the partitive:

Hän selittää suomea hitaasti. = He/She explains Finnish (language) slowly.
Opettaja opettaa suomea. = The teacher teaches Finnish.
Puhun suomea. = I speak Finnish.

Using suomea here suggests “(some) Finnish, the language in general, not as a completed whole thing.”
A form like selittää suomen would sound like “explain the entire Finnish language (completely)”, which is odd in everyday speech.

Why is hitaasti at the end, and could it go somewhere else?

Hitaasti (slowly) is an adverb of manner. A very natural place for it in Finnish is after the verb phrase, so you get:

opettaja selittää suomea hitaasti

Other positions are also possible and grammatical, with slight differences in emphasis:

opettaja selittää hitaasti suomea
opettaja hitaasti selittää suomea (more marked, focusing strongly on slowly)

But the most neutral, everyday order is usually:

[subject] [verb] [object] [adverb]
opettaja selittää suomea hitaasti

What is the difference between seurata kanavaa, katsoa kanavaa, and tilata kanava?

All three are common with media content, but their meanings differ:

seurata kanavaa = to follow a channel
- General, ongoing interest. You regularly pay attention to what happens there.
- Works also for news, sports, discussions, etc.: Seuraan tätä uutiskanavaa.
katsoa kanavaa = to watch a channel
- Focuses on actually watching (having it on the screen).
- Katson tätä kanavaa = I’m (currently) watching this channel / I watch this channel.
tilata kanava (esp. on YouTube etc.) = to subscribe to a channel
- A specific action of clicking “subscribe / follow”.
- After that, you can say: Seuraan sitä kanavaa (I follow that channel).

In the sentence, Seuraan kanavaa emphasizes ongoing following, not just a one-time act of watching or subscribing.

Could I also say Minä seuraan kanavaa, jossa opettaja selittää suomea hitaasti?

Yes.

Adding minä is grammatically correct. The difference is only in emphasis:

Seuraan kanavaa, jossa…
- Neutral: just states the fact I follow a channel…
Minä seuraan kanavaa, jossa…
- Emphasizes I (perhaps contrasting with others):
  - I follow a channel where the teacher explains Finnish slowly (but maybe others don’t).

In everyday speech and writing, dropping minä is more common when there’s no special contrast.

Could I say Seuraan kanavaa, jolla opettaja selittää suomea hitaasti instead of jossa? Would it change the meaning?

You will sometimes see both with kanava, but they use different local cases:

jossa = inessive of joka → literally “in which”
jolla = adessive of joka → literally “on which”

For media like TV or YouTube channels, Finnish often speaks of things happening on a channel (kanavalla), so:

Seuraan kanavaa, jolla opettaja selittää suomea hitaasti.
≈ I follow a channel on which the teacher explains Finnish slowly.

Your original:

Seuraan kanavaa, jossa opettaja selittää suomea hitaasti.
≈ I follow a channel where / in which the teacher explains Finnish slowly.

In practice, both usually convey the same idea. Jolla aligns more directly with the idea “on the channel”, while jossa feels more like “in that channel / in that space”, but in this abstract, online context the difference is small.