Dogovoreno je da svatko napiše po dvije rečenice za svaki padež.

It literally means It has been agreed or It was agreed.

This is an impersonal, passive-like Croatian structure:

• dogovoreno = past passive participle, neuter singular
• je = is/has auxiliary

There is no stated subject, so English usually adds it: It was agreed...

Croatian uses this kind of wording quite often when the speaker wants to focus on the result of an agreement rather than on who made it.

Because this is an impersonal construction.

In Croatian, when no real subject is named, the participle often appears in neuter singular by default. So dogovoreno je does not mean that some neuter thing was agreed; it is simply the standard way to say it was agreed without naming the people involved.

Da introduces a subordinate clause.

After expressions like it was agreed, it is important, I want, they decided, Croatian very often uses:

• da
  • a present-tense verb form

So:

• Dogovoreno je da... = It was agreed that...

In English, this can correspond to several patterns, such as:

• that everyone should write...
• that everyone would write...
• sometimes even for everyone to write...

Croatian normally prefers da here rather than an infinitive.

Svatko means everyone / each person.

It is used when you want to refer to people one by one as individuals. That fits this sentence well, because each person has the same task.

Compare:

• svatko = everyone, each person
• svi = all, everyone in a more straightforward plural sense

Both can be possible in some contexts, but svatko is especially natural when the idea is each person does their own share.

Because svatko is grammatically singular, even though its meaning includes many people.

So Croatian uses a singular verb:

• svatko napiše = everyone writes / should write

Not:

• svatko napišu

This is similar to English everyone is, not everyone are.

Because napiše is from the perfective verb napisati, while piše is from the imperfective verb pisati.

The difference is roughly:

• pisati / piše = writing as a process, ongoing activity
• napisati / napiše = to write and complete it

Here the agreement is about finishing a task: each person is supposed to produce two sentences. That is why napiše is the natural choice.

So the sentence focuses on the completed result, not just on the activity of writing.

Because after da, Croatian often uses present-tense forms to talk about a future, expected, intended, or required action.

So although napiše is formally a present form, here it does not mean that the writing is happening right now. It means something like:

• should write
• is to write
• will write, depending on context

This is very normal in Croatian subordinate clauses.

Here po is distributive.

It means:

• two each
• two apiece

So:

• svatko napiše po dvije rečenice = each person writes two sentences

The word po makes it especially clear that the quantity is assigned individually to each person.

Because after dva/dvije, tri, and četiri, Croatian uses a special counting form of the noun.

So:

• jedna rečenica
• dvije rečenice
• tri rečenice
• četiri rečenice

With rečenica, the form rečenice is exactly what you expect after dvije.

For learners, the simplest thing to remember is: after two, three, and four, Croatian nouns often do not behave the same way as after larger numbers.

The preposition za here means for, and it requires the accusative case.

So:

• za svaki padež = for each case

Why does padež stay the same?

Because padež is a masculine inanimate noun, and in Croatian the accusative singular of masculine inanimate nouns is the same as the nominative singular.

The adjective follows the same pattern here:

• nominative: svaki padež
• accusative: svaki padež

Same form, different function.

Yes. A common more personal version would be:

• Dogovorili smo se da svatko napiše po dvije rečenice za svaki padež.

That means We agreed that everyone should write two sentences for each case.

The difference is:

• Dogovoreno je... = impersonal, focuses on the agreement itself
• Dogovorili smo se... = personal, explicitly says we agreed

Both are natural.