Motivaationi kasvaa, kun työ edistyy.

The ending -ni is a possessive suffix meaning my.

So:

• motivaatio = motivation
• motivaationi = my motivation

Finnish often expresses possession by adding a suffix directly to the noun instead of using a separate word like my.

Not necessarily. Motivaationi already means my motivation by itself.

You can also say minun motivaationi, but that usually adds emphasis, contrast, or extra clarity.

So:

• motivaationi = my motivation
• minun motivaationi = my motivation, with stronger emphasis on my

Here, kasvaa is the 3rd person singular present tense: grows / is growing / increases.

It looks like the dictionary form because some Finnish verbs, especially ones ending in -aa / -ää, have a 3rd person singular present form that is spelled the same as the infinitive.

So in this sentence:

• motivaationi = subject
• kasvaa = main verb

That tells you it is a finite verb here, not just the infinitive.

Here kun means when or as. It introduces a subordinate clause that gives the time or situation for the main clause.

So the structure is:

• Motivaationi kasvaa = main clause
• kun työ edistyy = subordinate clause

In some other sentences, kun can also mean because, but in this sentence the when/as meaning is the natural one.

Because Finnish normally uses a comma to separate a main clause from a subordinate clause.

So:

• Motivaationi kasvaa, kun työ edistyy.

This is standard Finnish punctuation. English is sometimes less strict about commas in similar sentences, so this can feel surprising at first.

Because työ is the subject of the clause työ edistyy.

In ordinary affirmative sentences, the subject is usually in the nominative, which is the basic dictionary form. So:

• työ = work / the work
• edistyy = progresses

No extra case ending is needed on työ here.

Finnish does not have articles like a, an, or the.

So työ can mean things like:

• work
• the work
• sometimes a job/task, depending on context

Finnish leaves that information to context instead of marking it with an article.

Edistyy comes from the infinitive edistyä.

In this sentence, edistyy is 3rd person singular present tense, because its subject työ is singular.

A simple breakdown:

• edistyä = to progress, to advance
• edistyy = progresses, is progressing

So työ edistyy means that the work is moving forward.

Yes. Finnish word order is fairly flexible.

A very natural alternative is:

Kun työ edistyy, motivaationi kasvaa.

That version starts with the when-clause. The meaning stays the same, but the emphasis changes slightly.

The original sentence is a neutral and natural way to say it.

These words are tricky for English speakers because of y and ö.

• y is like German ü or French u
• ö is like German ö or French eu in peu

So:

• työ has a rounded front-vowel sound throughout
• edistyy ends in yy, which is a long vowel, so you hold that y sound a little longer

Also remember that Finnish usually stresses the first syllable of each word.