Zadovoljstvo je riješiti zagonetku.

The sentence is built like this:

• Zadovoljstvo = pleasure, a pleasure, satisfaction
• je = is
• riješiti = to solve
• zagonetku = a riddle / puzzle in the object form

So the structure is basically:

• [noun] + je + [infinitive phrase]

Literally, it is something like A pleasure is to solve a riddle, but in natural English it means It is a pleasure to solve a riddle or Solving a riddle is a pleasure.

Croatian often does not need a dummy subject like English it.

In English, we say:

• It is a pleasure to solve a riddle.

But that it does not really refer to anything. It is just there because English grammar usually wants a subject.

Croatian does not need that kind of placeholder, so it can simply say:

• Zadovoljstvo je riješiti zagonetku.

So Croatian is more direct here.

After expressions like It is nice to..., It is hard to..., It is a pleasure to..., Croatian often uses the infinitive, just as English uses to + verb.

So:

• riješiti = to solve

This infinitive phrase acts like the content of what is pleasurable:

• Zadovoljstvo je [riješiti zagonetku].

In other words, solving a riddle is what gives pleasure.

Riješiti is a perfective verb, meaning to solve with focus on reaching the result: the riddle gets solved.

Croatian verbs often come in aspect pairs:

• riješiti = perfective, to solve / to finish solving
• rješavati = imperfective, to be solving, to solve repeatedly, or focusing on the process

In this sentence, riješiti zagonetku sounds natural because the idea is the complete act of solving the riddle.

Compare:

• Zadovoljstvo je riješiti zagonetku. = It is a pleasure to solve a riddle.
• Zadovoljstvo je rješavati zagonetke. = It is a pleasure to solve / work on riddles in general, more process-oriented or habitual.

So riješiti points more to the completed achievement.

Because it is the direct object of riješiti.

The dictionary form is:

• zagonetka = riddle / puzzle

But after a verb like riješiti (to solve), the noun goes into the accusative case:

• riješiti zagonetku = to solve a riddle

This happens because zagonetka is a feminine noun in -a. For many feminine nouns, the singular accusative ends in -u:

• zagonetka → zagonetku
• knjiga → knjigu
• poruka → poruku

Yes, on the surface zadovoljstvo is the grammatical subject, and je agrees with it in the singular.

• zadovoljstvo is a neuter singular noun
• je is the 3rd person singular form of biti (to be)

So grammatically, the sentence is like:

• Zadovoljstvo = subject
• je = copula (is)
• riješiti zagonetku = infinitive phrase functioning as the complement

However, semantically, the sentence is about the action to solve a riddle being pleasurable.

Yes. Croatian word order is more flexible than English word order.

You can also say:

• Riješiti zagonetku je zadovoljstvo.

This puts more focus on the action itself: solving a riddle.

The original:

• Zadovoljstvo je riješiti zagonetku.

sounds a bit more like It is a pleasure to solve a riddle.

The alternative:

• Riješiti zagonetku je zadovoljstvo.

is closer to To solve a riddle is a pleasure.

Both are grammatical. The difference is mostly one of emphasis and style.

It can suggest both, depending on context.

Zadovoljstvo often means:

• pleasure
• satisfaction
• enjoyment

In this sentence, the most natural English equivalent is usually pleasure:

• It is a pleasure to solve a riddle.

But there is also a shade of satisfaction in the sense that solving something difficult feels rewarding.

So the word has a slightly broader meaning than a single English word sometimes captures.

The sentence is understandable and grammatical, but in everyday speech a speaker might often say something a bit more idiomatic, for example:

• Pravo je zadovoljstvo riješiti zagonetku. = It is a real pleasure to solve a riddle.
• Riješiti zagonetku pravo je zadovoljstvo.
• Baš je zadovoljstvo riješiti zagonetku.

The original sentence is fine, but adding pravo or baš can make it sound a bit more natural or expressive.

A rough pronunciation guide:

• riješiti ≈ ree-YESH-ee-tee
• zagonetku ≈ za-go-NET-koo
• zadovoljstvo ≈ za-do-VOL-stvo

A few helpful points:

• rj in riješiti can be tricky for English speakers
• š sounds like English sh
• j in Croatian sounds like English y
• je is usually pronounced like ye

So riješiti begins something like rye-ye... compressed together, not like English ree-j.

Yes, this reflects an important Croatian tendency: short unstressed forms, called clitics, often appear in second position in the clause.

Here, je is a clitic form of biti (to be), and it comes after the first element:

• Zadovoljstvo je riješiti zagonetku.

If you move another element to the front, the clitic often follows that instead:

• Riješiti zagonetku je zadovoljstvo.

So for learners, it is useful to remember that short forms like je often do not stay rigidly in the same place as English is.

Yes, that is possible, but it changes the style.

Compare:

• Zadovoljstvo je riješiti zagonetku.
  = It is a pleasure to solve a riddle.

• Zadovoljstvo je rješavanje zagonetke.
  = The solving of a riddle is a pleasure / Solving a riddle is a pleasure.

The version with the infinitive (riješiti) usually sounds lighter and more verbal, while the version with the verbal noun (rješavanje) sounds a bit more abstract or formal.

So both can work, but they are not identical in tone.

It can mean both, depending on context.

Most commonly:

• zagonetka = riddle
• but it can also be used more broadly for an enigma, mystery, or sometimes a puzzle

So riješiti zagonetku may mean:

• to solve a riddle
• to solve a puzzle
• in some contexts, even to figure out a mystery

The exact English translation depends on the situation.