Learn Hardcore Croatian: Ona je otišla iz sobe bez da kaže “laku noć”. - She left the room without saying “good night”.

You can drop ona because the participle otišla already shows feminine singular, so the subject is clear from context. But in Croatian the auxiliary je cannot normally stand in first position; it tends to appear in the so‑called “second position” in the sentence, often after the first stressed word (here ona or otišla).

Why is it iz sobe and not something like od sobe or s sobe?

In Croatian, the choice of preposition with verbs of movement is very fixed:

iz
- genitive → movement out of an enclosed space
od
- genitive → from (a person, origin, source, distance)
s / sa
- genitive or instrumental → from/off a surface or with someone/something

Since a room is an enclosed space you are leaving from the inside, iz is the natural preposition:

iz sobe – out of the room

Using od sobe or s sobe here would sound wrong to native speakers.

What case is sobe in, and why?

Sobe is in the genitive singular.

The noun:

nominative: soba (room)
genitive: sobe

The preposition iz (out of, from inside) always governs the genitive:

iz sobe – out of the room
iz kuće – out of the house
iz škole – out of the school

So the form sobe is required by the preposition iz.

What exactly does bez mean here, and how does bez da work?

Bez by itself is a preposition meaning without, and it usually takes the genitive:

bez šećera – without sugar
bez problema – without problems

In bez da kaže laku noć, bez combines with da and a finite verb:

bez da kaže – literally without that she/he says, functionally without saying

This bez da + finite verb construction is very common in everyday speech, but many grammarians consider it somewhat colloquial or non‑standard. A more strictly standard version would be something like:

… a da ne kaže laku noć
… a da nije rekla laku noć
… bez da joj je rekla laku noć (if there is an indirect object)

Still, you will hear bez da kaže extremely often in natural spoken Croatian.

Why is it bez da kaže and not bez da je rekla or bez reći?

All of these are possible; they just differ in style and nuance.

bez da kaže laku noć
- Most colloquial, very natural in speech.
- Uses da
  - present tense (kaže) to express something that does not happen.
bez da je rekla laku noć
- Sounds somewhat more standard and explicit.
- Emphasizes the action in the past, matching je otišla:
  Ona je otišla … bez da je rekla laku noć.
bez reći laku noć
- Uses the verbal noun reći (saying).
- More compact, a bit more formal/literary:
  Ona je otišla iz sobe bez reći laku noć.

So the sentence in your example is perfectly natural in everyday spoken language, but alternative forms are also possible and sometimes preferred in formal writing.

Why is the verb kaže in the present tense, when the whole sentence is in the past?

With da‑clauses of this type, Croatian often uses a present‑tense form to express something that is (not) happening relative to the main action, not relative to the absolute time.

Ona je otišla iz sobe bez da kaže laku noć.
→ She left the room, and in the course of leaving she does not say good night.

Grammatically, kaže is present simple (3rd person singular), but after da it takes on a function similar to a subjunctive in some other languages: it expresses a non‑realized or hypothetical action.

You could also use the perfect in the da‑clause:

… bez da je rekla laku noć.

This shifts the focus to the completed action (or rather, its non‑completion) and is often considered more “correct” in careful standard language, though bez da kaže is very common in speech.

Could we say Ona je otišla iz sobe a da ne kaže laku noć instead of bez da kaže laku noć?

Yes, and many would consider that more standard:

Ona je otišla iz sobe, a da ne kaže laku noć.

Here a da ne kaže literally means and (so) that she does not say. The conjunction a plus da ne is a common way to express that one action happens without another expected action.

Semantically, it’s very close to bez da kaže, but:

bez da kaže → colloquial, direct, very common in speech.
a da ne kaže → sounds slightly more careful/standard and explicitly negative (ne).

Why do we say laku noć and not something like dobra noć?

Laku noć is a fixed, idiomatic expression meaning good night (as a farewell before sleeping).

lak (masc.), laka (fem.), lako (neuter) = light, easy
noć = night, feminine noun

The basic phrase is laka noć (light/easy night), but when used as a direct wish or greeting, the adjective goes into the accusative because we are effectively saying (Želim ti) laku noć – (I wish you) a good night.

So:

nominative: laka noć
accusative: laku noć → used as the standard expression.

Dobra noć exists, but it is much less common and not the usual way to say good night in Croatian. The idiomatic farewell is Laku noć!

Why is laku in the accusative? There is no obvious object like in English.

In Croatian, greetings and wishes often use an adjective + noun in the accusative, even when the verb is omitted:

(Želim ti) laku noć. – (I wish you) a good night.
(Želim ti) sretan rođendan. – (I wish you) a happy birthday.

The verb želim (I wish) is usually implied and left out, but the case stays accusative as if the full sentence were present.

In bez da kaže laku noć, laku noć is what she would say, so it stays in the same form as in the usual expression Rekla je: Laku noć. – here laku noć is the content of the utterance in accusative.

Can the word order change? For example: Ona je bez da kaže laku noć otišla iz sobe?

Yes, Croatian allows quite flexible word order, especially to change emphasis or style.

Possible variants include:

Ona je otišla iz sobe bez da kaže laku noć. (neutral, very natural)
Otišla je iz sobe bez da kaže laku noć. (slight focus on the verb leaving)
Ona je bez da kaže laku noć otišla iz sobe. (emphasizes the without saying good night part)

All are grammatically acceptable, though the original is the most neutral and common in everyday speech.

Is bez da kaže laku noć considered fully correct in formal written Croatian?

This is a matter of style and prescriptive vs. descriptive grammar:

In real usage, especially in speech and informal writing, bez da kaže laku noć is completely natural and extremely common.
Some conservative grammars and style guides regard bez da
- finite verb as colloquial or non‑standard. In careful formal writing, they often recommend alternatives like:
  - … a da ne kaže laku noć.
  - … bez da je rekla laku noć.
  - … bez da joj je rekla laku noć. (if specifying whom she says it to)
  - … bez da joj kaže laku noć.

So for everyday conversation and informal text, your sentence is fine. For very formal or exam‑style writing, you might prefer one of the alternatives above.

Could I say Ona je napustila sobu bez da kaže laku noć or Ona je izašla iz sobe bez da kaže laku noć? Are they different from otišla?

Yes, both are possible, with slight nuances:

Ona je otišla iz sobe …
- Neutral she left the room; focus on the fact that she went away.
Ona je izašla iz sobe …
- izaći (iz) emphasizes the act of going out (of) the room; more spatial.
Ona je napustila sobu …
- napustiti = to leave/abandon, sounds a bit more formal and can sometimes imply a stronger or more intentional departure.

All three work in this context. Otišla iz sobe and izašla iz sobe are the most typical everyday choices.