Learn Hardcore Finnish: Ystävällisyys ja rohkeus ovat tärkeitä, kun opimme uutta kieltä. - Friendliness and courage are important when we learn a new language.

Ystävällisyys ja rohkeus is a compound subject (two things joined by ja), so Finnish treats it as plural.
→ The verb olla has to be plural: ovat, not on.
The base adjective is tärkeä (important). Its main forms are:
- singular nominative: tärkeä
- singular partitive: tärkeää
- plural nominative: tärkeät
- plural partitive: tärkeitä
Predicate adjectives after olla can be in nominative or partitive. Both are possible with a plural subject, but they have a nuance difference:
- Ystävällisyys ja rohkeus ovat tärkeät
  = they are the important ones (more like identifying them as a specific set).
- Ystävällisyys ja rohkeus ovat tärkeitä
  = they are important (qualities) in general; this is more natural here.

So ovat tärkeitä matches the plural subject and presents “being important” as a general quality.

What exactly are ystävällisyys and rohkeus grammatically?

They are abstract nouns formed from adjectives:

ystävällinen (kind, friendly) → ystävällisyys (kindness, friendliness)
- Pattern: many -inen adjectives form an abstract noun with -isyys / -yys.
- Meaning: the quality of being friendly or kind.
rohkea (brave) → rohkeus (courage, bravery)
- Pattern: many adjectives form abstract nouns with -us / -ys.
- Meaning: the quality of being brave.

Although they refer to general, often uncountable qualities (like kindness in English), grammatically they are singular nouns in the nominative case here.

Which case is uutta kieltä, and what does it tell us?

Both words are in the partitive singular:

uutta = partitive singular of uusi (new)
kieltä = partitive singular of kieli (language)

The partitive object here signals:

An ongoing / incomplete process
- opimme uutta kieltä = we are in the process of learning a new language (not “we have fully learned it”).
Indefinite amount / non‑specificity
- It’s like saying “some new language” / “a new language” in general, not pointing to a specific, completed “whole language”.

If you used a total object instead, you’d say e.g.:

opimme uuden kielen = we (will) learn / have learned that new language (as a whole, a more complete achievement).

So uutta kieltä fits the idea of learning in general, not having fully learned.

Why does the adjective also change: why uutta kieltä, not uusi kieltä?

In Finnish, adjectives must agree with the noun they modify in:

Case
Number
(and often) possessive endings, if any

Since kieltä is partitive singular, the adjective uusi must also be partitive singular:

nominative: uusi kieli (a new language)
partitive: uutta kieltä (some/any new language, as an object of an ongoing action)

More examples of agreement:

kaksi uutta kieltä – two new languages (both uutta and kieltä are partitive singular)
monia uusia kieliä – many new languages (both uusia and kieliä are partitive plural)

So uusi kieltä would be ungrammatical; the cases must match.

Why is there no word for a or the in uutta kieltä?

Finnish does not have articles like a / an / the.

Definiteness and indefiniteness are expressed by:

Context
Word order
Case choice (e.g. partitive vs. total object)
Sometimes by demonstratives like se (that/it), tämä (this), etc.

So uutta kieltä can be understood as:

“a new language” (indefinite, general)
in some contexts, “the new language (we’re learning)” – if it’s clear from context which one

But there is no separate article word. The partitive here mainly tells you about the type of object (ongoing / partial), not about “a vs. the”.

What does kun mean here, and how is it different from koska?

In this sentence, kun introduces a time clause:

kun opimme uutta kieltä = when we (are) learning a new language

Comparison:

kun
- primary meaning: when
- can also mean as / whenever / while depending on context.
koska
- primary meaning: because (gives a reason)
- answers “why?”

So:

Ystävällisyys ja rohkeus ovat tärkeitä, kun opimme uutta kieltä.
= Kindness and courage are important when we learn a new language.

If you used koska:

Ystävällisyys ja rohkeus ovat tärkeitä, koska opimme uutta kieltä.
= Kindness and courage are important because we are learning a new language.

In casual speech, some Finns use kun where standard Finnish would use koska, but in careful writing they are kept separate as when vs. because.

What tense and person is opimme, and how is it formed?

Opimme is:

Present tense
1st person plural (“we”)
From the verb oppia (to learn)

The personal forms of oppia in the present are roughly:

minä opin – I learn
sinä opit – you learn
hän oppii – he/she learns
me opimme – we learn
te opitte – you (pl) learn
he oppivat – they learn

Points to notice:

The ending -mme marks “we”.
The single p in opimme (not oppimme) is due to consonant gradation: some forms use weak grade p, others strong grade pp (like oppii, oppivat).

So opimme alone already tells you “we learn / we are learning”.

Why is there no me before opimme?

Finnish is a pro‑drop language: subject pronouns are often omitted because the verb ending already shows the person and number.

kun opimme uutta kieltä
= when we learn a new language

You can add me for emphasis or contrast:

kun me opimme uutta kieltä
≈ when we (as opposed to someone else) learn a new language

So the version without me is the neutral, default one. The meaning “we” is already built into -mme.

Can the word order in kun opimme uutta kieltä be changed?

Yes, Finnish word order is fairly flexible, but not all changes are equally neutral.

Neutral, standard order in this clause:
kun opimme uutta kieltä
(subordinator – verb – object)

You can move the object for emphasis:

kun uutta kieltä opimme
- Emphasises uutta kieltä (it’s a new language, not something else).
- Feels more contrastive or stylistic, less “plain neutral”.

The subordinator kun must stay at the beginning of its clause; you don’t move it away from opimme.

So yes, order can change, but kun opimme uutta kieltä is the most straightforward, natural variant.

Why is there a comma before kun in the Finnish sentence?

Finnish comma rules are different from English ones.

Rule of thumb: a subordinate clause (introduced by kun, koska, että, jos, vaikka, koska etc.) is separated by a comma from the main clause, regardless of order.

Here:

Main clause: Ystävällisyys ja rohkeus ovat tärkeitä
Subordinate clause: kun opimme uutta kieltä

So standard punctuation is:

Ystävällisyys ja rohkeus ovat tärkeitä, kun opimme uutta kieltä.

In English, “Kindness and courage are important when we are learning a new language” might or might not have a comma, but in Finnish the comma is required in this structure.

Why is it ystävällisyys ja rohkeus and not ystävällinen ja rohkea?

Because the sentence talks about the qualities themselves, not about a person who has them.

ystävällisyys = kindness / friendliness (the abstract quality)
rohkeus = courage / bravery (the abstract quality)

If you used the adjectives ystävällinen and rohkea, they would need a noun to modify:

ystävällinen ja rohkea ihminen
= a kind and brave person

So:

Ystävällisyys ja rohkeus ovat tärkeitä...
= Kindness and courage are important...

is talking about the values / traits.

Ystävällinen ja rohkea ihminen on tärkeä...
= A kind and brave person is important...

would talk about a person.

Using the abstract nouns is the natural way to say that these qualities are important.

Are ystävällisyys and rohkeus normally singular like this, or can they be plural too?

They are normally singular when referring to the abstract quality:

Ystävällisyys on tärkeää. – Kindness is important.
Rohkeus auttaa meitä. – Courage helps us.

You can make them plural, but then the meaning changes:

ystävällisyydet – acts/kinds of kindness
rohkeudet – kinds/displays of courage

These plurals are much less common and feel more concrete or countable (like “instances of kindness”) rather than the general idea of “kindness”.

In your sentence, ystävällisyys ja rohkeus are correctly singular because they refer to the general qualities.