Learn Hardcore Croatian: Napisavši iskrenu poruku, ona je odjednom osjetila mirniju atmosferu u kući. - Having written a sincere message, she suddenly felt a calmer atmosphere in the house.

Napisavši is a past verbal adverb (in Croatian: glagolski prilog prošli). It roughly corresponds to English structures like “having written” or “after writing”.

Formation from napisati (to write, perfective):

Take the L-participle (the form you use in the past tense): napisao / napisala
Remove the gender/number endings: napisa-
Add -vši: napisavši

Use:

It describes an action completed before the main verb of the sentence:
- Napisavši iskrenu poruku, ona je osjetila…
  ≈ Having written / After writing an honest message, she felt…
It is always short and shares the subject with the main clause (the subject of napisavši is ona).

Why is there a comma after Napisavši iskrenu poruku?

The part Napisavši iskrenu poruku is an adverbial clause expressed with a verbal adverb. It functions like “after she wrote an honest message”.

In Croatian, such introductory adverbial phrases are separated by a comma from the main clause:

Napisavši iskrenu poruku, ona je…
Kada je napisala iskrenu poruku, ona je… (also takes a comma)

So the comma marks the boundary between the circumstance (what happened first) and the main action.

Why is it iskrenu poruku and not iskrena poruka?

Iskrenu poruku is in the accusative case, because it is the direct object of the (understood) verb napisavši (from napisati = to write something).

Nominative (dictionary form):
- iskrena poruka – “an honest message” (as a subject)
Accusative (direct object, feminine singular):
- iskrenu poruku – “an honest message” (as something written)

Both the noun and the adjective change:

poruka → poruku (feminine singular accusative)
iskrena → iskrenu (adjective agrees with the noun: feminine, singular, accusative)

Why is poruku (accusative) used with napisavši if the verb is not explicitly there as je napisala?

Even though napisavši looks different, it still acts like a verb and keeps its usual valency:

From napisati nešto = “to write something” (that nešto is accusative).
Napisavši iskrenu poruku = “Having written an honest message” – the thing written (poruku) is still the direct object in the accusative.

So the case requirements of the base verb (napisati) remain in force in the phrase with napisavši.

Could I say Kad je napisala iskrenu poruku, ona je odjednom osjetila… instead of Napisavši iskrenu poruku…? Is there any difference?

Yes, you can say:

Kad je napisala iskrenu poruku, ona je odjednom osjetila mirniju atmosferu u kući.

The main differences are style and focus:

Napisavši…
- More compact, stylistically a bit more literary/formal.
- Emphasizes that the first action was completed right before the main action.
Kad je napisala… / Nakon što je napisala…
- Feels more neutral / conversational.
- Also clearly expresses a sequence: first she wrote, then she felt.

In meaning, they are almost the same here; the choice is mostly stylistic.

Why is ona (she) explicitly mentioned? Could we just say Napisavši iskrenu poruku, odjednom je osjetila…?

Yes, you can absolutely drop ona:

Napisavši iskrenu poruku, odjednom je osjetila mirniju atmosferu u kući.

Croatian usually omits subject pronouns when the subject is clear from the verb ending and context.

Using ona:

adds a bit of emphasis (“she felt it”), or
can help avoid ambiguity if there are multiple possible female subjects in the context.

But grammatically, ona is not required.

Why is the word order ona je odjednom osjetila, and where does je have to go?

Je is an auxiliary clitic (for the past tense). Croatian has a rule that clitics tend to go in second position in the clause.

In ona je odjednom osjetila:

ona = first (a full word)
je = second position (clitic)
then the rest: odjednom osjetila…

Some other acceptable orders (with slightly different emphasis):

Odjednom je ona osjetila…
Ona je osjetila odjednom mirniju atmosferu… (less natural, but possible)

What you generally cannot do is move je out of its clitic position, e.g.
✗ Ona odjednom je osjetila… (sounds wrong).

What exactly does odjednom mean, and can it be placed somewhere else in the sentence?

Odjednom means “suddenly / all of a sudden”.

Placement:

Ona je odjednom osjetila mirniju atmosferu u kući.
Odjednom je osjetila mirniju atmosferu u kući.
Ona je osjetila odjednom mirniju atmosferu u kući. (possible, but less common)

It is fairly flexible in position, but it tends to appear near the verb. Moving it to the very beginning (Odjednom je…) puts a bit more emphasis on the suddenness.

Why is it je osjetila (perfect tense) and not je osjećala?

Osjetila (from osjetiti) is a perfective verb form in the past tense.
Osjećala (from osjećati) is imperfective.

je osjetila → a single, completed act of feeling/noticing something
- Here: she suddenly noticed a calmer atmosphere.
je osjećala → a continuous or repeated state in the past
- Example: Tih dana je osjećala mirniju atmosferu u kući.
  “Those days she was feeling a calmer atmosphere in the house.”

Because we have odjednom (“all of a sudden”) and a sudden change, the perfective (osjetila) is the natural choice.

What form is mirniju in mirniju atmosferu, and why isn’t it just mirna atmosfera?

Mirniju is:

comparative degree of miran = “calm, peaceful”
feminine, singular, accusative
agreeing with atmosferu (accusative of atmosfera)

Paradigm (feminine singular):

Nominative: mirna atmosfera – “a calm atmosphere”
Accusative: mirnu atmosferu – “a calm atmosphere” (as object)
Comparative nominative: mirnija atmosfera – “a calmer atmosphere”
Comparative accusative: mirniju atmosferu – “a calmer atmosphere” (as object)

In the sentence, osjetila je mirniju atmosferu → atmosferu is a direct object (accusative), so the adjective must be mirniju (fem. sg. acc. comparative), not mirnija.

Why is it atmosferu and not atmosfera?

Atmosferu is the accusative singular of atmosfera.

Nominative: atmosfera – used for the subject
- Atmosfera je mirna. – “The atmosphere is calm.”
Accusative: atmosferu – used for the direct object
- Ona je osjetila atmosferu. – “She felt the atmosphere.”

In the sentence, ona je osjetila mirniju atmosferu → “atmosphere” is the thing she felt, so it must be in the accusative: atmosferu.

Why is it u kući and not u kuću?

The preposition u can take either:

Accusative → movement into somewhere
- Idem u kuću. – “I am going into the house.”
Locative → being in/at a place (no movement)
- Ona je u kući. – “She is in the house.”

In mirniju atmosferu u kući, the phrase describes where the calmer atmosphere is: in the house, not movement towards the house, so we use locative:

kuća (nominative)
u kući (locative: in the house)

Can the phrase u kući be moved elsewhere in the sentence?

Yes, Croatian word order is fairly flexible. All of these are possible:

Napisavši iskrenu poruku, ona je odjednom osjetila mirniju atmosferu u kući.
Napisavši iskrenu poruku, ona je u kući odjednom osjetila mirniju atmosferu. (less usual, but grammatical)
U kući je, napisavši iskrenu poruku, odjednom osjetila mirniju atmosferu. (more marked, stylistic)

The most natural is usually to keep u kući close to atmosferu, since it describes where that atmosphere is:

…osjetila mirniju atmosferu u kući.