Learn Hardcore Finnish: Opettajan näkökulma oli, että ruutuaika ei ole pahasta, jos se pysyy kohtuullisena. - The teacher’s point of view was that screen time is not a bad thing if it stays moderate.

Literally, opettajan näkökulma means “the teacher’s point of view” or “the teacher’s perspective”.
In Finnish, possession is often expressed with the genitive:

opettajan kirja = the teacher’s book
ystävän auto = the friend’s car
opettajan näkökulma = the teacher’s point of view

If you used opettaja näkökulma, it would be ungrammatical, because a noun that owns another noun normally has to be in the genitive form.

2. What does näkökulma oli, että … do in this sentence? Is it like “the teacher thought that …”?

The structure X:n näkökulma oli, että … literally means:

“X’s point of view was that …”

Functionally, it’s very close to English “X thought that …” or “according to X …”, but it sounds slightly more formal/neutral and emphasizes that this is a perspective rather than just a passing thought.

So:

Opettajan näkökulma oli, että …
≈ The teacher’s point of view was that …
≈ The teacher thought that … / According to the teacher …

Grammatically:

näkökulma = subject
oli (past tense of olla) = main verb
the että-clause = a content clause explaining what the point of view actually was.

3. What exactly is ruutuaika? Is it a common word?

Yes, ruutuaika is common modern vocabulary. It’s a compound:

ruutu = screen (also “square”, “grid”)
aika = time

Together: ruutuaika = “screen time” (time spent using screens: phones, tablets, computers, TV).

You’ll see it a lot in discussions about children, media, and health:

Liiallinen ruutuaika voi olla haitallista.
Too much screen time can be harmful.

In the sentence:

ruutuaika ei ole pahasta
= screen time is not a bad thing / not harmful

4. Why is it ei ole pahasta instead of something like ei ole paha?

Ei ole pahasta is a fixed, idiomatic expression.

paha = bad, evil
pahasta = elative case (“from / out of bad” literally)

But in idiomatic use:

olla pahasta (jollekulle / jollekin)
literally: to be from bad (for someone)
actually means: to be bad / harmful / not advisable (for someone/something)

So:

Se ei ole pahasta.
= It’s not a bad thing (it’s not harmful).

Compare:

On pahasta valvoa joka yö myöhään.
It’s bad / harmful to stay up late every night.

If you said ei ole paha, it’s more like “it isn’t bad” in a very general, loose sense, but it doesn’t have the same “harmful / not a problem” idiomatic flavor that ei ole pahasta has. In this context, with ruutuaika, the idiom is exactly what is normally used.

5. What case is pahasta, and what does that case usually mean?

Pahasta is the elative singular of paha.

Elative is the -sta / -stä case, and its basic meaning is “out of / from”. Typical examples:

talosta = out of / from the house (talo → talosta)
Suomesta = from Finland (Suomi → Suomesta)
vesilasista = from the glass of water (vesilasi → vesilasista)

With adjectives like paha, elative often appears in idioms:

ei ole pahasta = is not a bad / harmful thing
on pahasta = is a bad / harmful thing
hyvästä (from hyvä = good) in some expressions:
Se tulee vain hyvästä. = It can only lead to something good.

So, while elative is “from/out of” in core meaning, in ei ole pahasta you just learn it as part of the idiom.

6. Why is it jos se pysyy kohtuullisena, and what is the role of kohtuullisena with pysyy?

The verb pysyä (to stay, remain) often takes the essive case -na / -nä to describe the state something remains in.

kohtuullinen = reasonable, moderate (adjective)
kohtuullisena = essive form: “as reasonable”, “in a reasonable state”

So:

pysyä kohtuullisena = to stay reasonable / remain at a reasonable level

Other examples with pysyä + essive:

pysyä rauhallisena = to stay calm
pysyä terveenä = to stay healthy
pysyä hengissä (slightly irregular form but same idea) = to stay alive

So jos se pysyy kohtuullisena means:

if it stays reasonable/moderate (referring to the amount of screen time).

7. What does jos mean here, and how is it different from kun?

Jos is the normal word for “if” (a condition).

jos se pysyy kohtuullisena = if it stays moderate

Kun can mean “when” (time) or sometimes “since/because”, and it can also appear in some conditional-like meanings, but here jos is the straightforward and natural choice because we’re talking about a condition:

Condition:
Ruutuaika ei ole pahasta, jos se pysyy kohtuullisena.
Screen time is not a bad thing, if it stays moderate.

If you replaced it with kun, it would start to sound more like a temporal “when it stays moderate”, which doesn’t really fit as well in a general statement about conditions.

8. Why is there a comma before jos se pysyy kohtuullisena?

In Finnish punctuation, a subordinate clause (like one starting with jos, “if”) is usually separated from the main clause by a comma, even when the subordinate clause comes after the main clause.

Main clause: ruutuaika ei ole pahasta
Subordinate (if-) clause: jos se pysyy kohtuullisena

So you write:

Ruutuaika ei ole pahasta, jos se pysyy kohtuullisena.

If you reverse the order, you also keep the comma:

Jos se pysyy kohtuullisena, ruutuaika ei ole pahasta.

Both orders are correct; the comma marks the boundary between the clauses.

9. Why do we have oli in the past tense, but ei ole and pysyy in the present? Wouldn’t everything need to be past?

Finnish is quite flexible with tense in reported speech or reported opinions.

Opettajan näkökulma oli, että …
→ tells you when the teacher had that point of view: in the past.

Inside the että-clause, we are talking about something that is generally true or true now from the teacher’s perspective. So it uses the present tense:

ruutuaika ei ole pahasta (present)
jos se pysyy (present)

This is similar to English:

The teacher’s view was that screen time *is not a bad thing if it stays moderate.*

English also keeps the inner clause in the present to talk about a general truth or still-valid opinion. Finnish works the same way here. You could put everything in the past in some contexts, but it would change the nuance to something like “back then, it wasn’t bad if it stayed moderate”, which is not what is meant here.

10. What does the se refer to in jos se pysyy kohtuullisena?

Se is a 3rd person singular pronoun here, referring back to ruutuaika (screen time).

Finnish pronouns:

hän = he / she (for people, more formal/written)
se = it (and in spoken language, often used for people too)

In standard written Finnish, se is perfectly normal for things and abstract concepts:

Ruutuaika (screen time) → se (it)

So:

jos se pysyy kohtuullisena
= if it (the screen time) stays moderate