Osaaminen on tärkeää, kun työ muuttuu.

Osaaminen is a noun meaning something like skills, competence, know-how, or ability.

It comes from the verb osata = to know how to / to be able to.

So osaaminen is not one single skill in a narrow sense. It is more like having the necessary knowledge and ability.

It is a noun.

Even though it is built from a verb, Finnish often creates nouns this way:

• osata = to know how to
• osaaminen = knowing how, competence, ability

This -minen form is very common in Finnish. It turns a verb into a noun:

• lukea = to read → lukeminen = reading
• tehdä = to do/make → tekeminen = doing/making
• oppia = to learn → oppiminen = learning

So osaaminen is grammatically a noun, and in this sentence it is the subject.

This is a very common question.

Here tärkeää is the partitive singular form of tärkeä.

In sentences like this, Finnish often uses the partitive form of the adjective when the subject is:

• abstract
• general
• uncountable / not a specific individual thing

So:

• Osaaminen on tärkeää. = competence/skills are important
• Työ on tärkeää. = work is important
• Rakkaus on tärkeää. = love is important

But if you are talking about a specific, countable thing, you usually use the basic form:

• Tämä taito on tärkeä. = this skill is important
• Se kirja on tärkeä. = that book is important

So tärkeää is used because osaaminen here is a general abstract idea, not one specific item.

On is the third person singular of olla = to be.

So:

• minä olen = I am
• sinä olet = you are
• hän on = he/she is
• se on = it is

In this sentence, Osaaminen on tärkeää, it simply means is.

Here kun means when.

It introduces a time clause:

• kun työ muuttuu = when work changes

Finnish kun can sometimes also mean things like as, since, or while, depending on context, but in this sentence when is the natural meaning.

Because in Finnish, a subordinate clause is normally separated by a comma.

So the main clause is:

• Osaaminen on tärkeää

And the subordinate clause is:

• kun työ muuttuu

Finnish punctuation does this very regularly:

• Tulen, kun ehdin. = I’ll come when I have time.
• On hyvä, että olet täällä. = It’s good that you’re here.

So the comma here is normal Finnish grammar.

Because työ is the subject of the clause työ muuttuu.

In Finnish, the subject is often in the nominative (basic dictionary form):

• työ = work
• työ muuttuu = work changes

There is no ending here because it is just the normal subject form.

Muuttuu is the third person singular present tense of muuttua.

• muuttua = to change, to become different
• muuttuu = changes / is changing

So:

• työ muuttuu = work changes / work is changing

The ending -u/-y + u/ü pattern is just part of how this verb conjugates.

A few examples:

• Minä muutun = I change
• Työ muuttuu = work changes
• Asiat muuttuvat = things change

Because muuttua and muuttaa are different verbs.

• muuttua = to change / to become changed
  
  • something changes by itself
• muuttaa = to change something / to alter, and also to move house

So:

• Työ muuttuu. = Work changes.
• Yritys muuttaa työaikoja. = The company changes working hours.

In your sentence, work is the thing that changes, so muuttuu is the correct choice.

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

So osaaminen can mean things like:

• competence
• the competence
• skills
• the skills

And työ can mean:

• work
• the work
• a job
• the job

The exact meaning depends on context.

In this sentence, both nouns are being used in a general sense, so English often translates them with broad meanings like skills or work.

Because Finnish and English do not always package ideas the same way.

For example:

• osaaminen is singular in form
• but in English, the natural translation may be skills or competence

This is very common with abstract nouns. Finnish may use one singular noun where English prefers:

• a mass noun: competence
• or a plural: skills

So the Finnish singular does not always mean one single item.

It has two parts:

1. Osaaminen on tärkeää

   • subject: osaaminen
   • verb: on
   • predicate adjective: tärkeää

2. kun työ muuttuu

   • conjunction: kun
   • subject: työ
   • verb: muuttuu

So the whole structure is:

[Main clause] + [subordinate clause]

That is a very common pattern in Finnish.

Yes, Finnish word order is fairly flexible, although this version is the most neutral and natural.

For example, you could also say:

• Kun työ muuttuu, osaaminen on tärkeää.

This puts more focus on the when work changes part first.

Both are grammatical, but:

• Osaaminen on tärkeää, kun työ muuttuu. = neutral, starts with the main point
• Kun työ muuttuu, osaaminen on tärkeää. = emphasizes the situation first

Usually it is understood as work in general.

That is because:

• työ has no extra word like tämä = this
• the whole sentence sounds like a general statement
• osaaminen is also used in a broad, abstract way

So the sentence feels like a general truth or principle, not a description of one particular job.