Ona właśnie wychodzi z domu.

Yes — Polish often omits subject pronouns because the verb ending already shows who is doing the action.

Here, wychodzi already means he/she/it is leaving / goes out, so ona is not required.

• Wychodzi z domu. = She is leaving the house / home.
• Ona wychodzi z domu. = same basic meaning, but ona adds emphasis, contrast, or clarity.

A speaker might include ona if:

• they want to stress she in particular,
• they are contrasting her with someone else,
• or they want to avoid ambiguity in context.

Właśnie often means just, right now, or exactly at this moment.

In this sentence, it emphasizes that the action is happening now or at this very moment.

So it gives the sentence a sense like:

• She is just leaving the house
• She is leaving the house right now

Be aware that właśnie can also have other meanings in different contexts, such as exactly or that’s right.

Wychodzić is the dictionary form (the infinitive), meaning to go out / to leave.

In the sentence, you need the conjugated form, because the action is being done by she.
For ona, the correct present-tense form is wychodzi.

Conjugation of wychodzić in the present tense:

• ja wychodzę
• ty wychodzisz
• on/ona/ono wychodzi
• my wychodzimy
• wy wychodzicie
• oni/one wychodzą

So ona wychodzi = she is going out / leaving.

Because after the preposition z meaning from/out of, Polish requires the genitive case.

The noun dom changes in the genitive singular to domu.

So:

• nominative: dom
• genitive: domu

That is why you say:

• z domu = from the house / out of the house / from home

This is a very common pattern in Polish:

• z pracy = from work
• z pokoju = from the room
• z miasta = from the city

Domu is in the genitive singular.

It appears in the genitive because the preposition z normally takes the genitive when it means from or out of.

So in z domu:

• z = from/out of
• domu = genitive form of dom

This is something learners need to memorize with prepositions: many Polish prepositions require a specific case.

It can mean either, depending on context.

In Polish, dom can mean:

• house as a building
• home as the place where someone lives

So wychodzi z domu may be understood as:

• she is leaving the house
• she is leaving home

Usually the situation makes it clear which is more natural.

Because Polish uses the present tense of an imperfective verb for actions happening right now.

The verb wychodzić is imperfective, and its present tense can describe:

• a current action,
• a habitual action,
• or a near-future action, depending on context.

So wychodzi can mean things like:

• is leaving
• goes out
• leaves

Here, because of właśnie, the most natural interpretation is a current action: she is just leaving.

Wychodzić is imperfective.

That means it focuses on:

• the process,
• repeated action,
• or an action in progress.

Its perfective partner is usually wyjść.

Compare:

• Ona właśnie wychodzi z domu. → imperfective, action in progress / happening now
• Ona wyjdzie z domu. → perfective future, she will leave the house
• Ona wyszła z domu. → perfective past, she left the house

For a sentence describing what is happening at this moment, the imperfective wychodzi is the normal choice.

Yes.

Without more context, ona wychodzi z domu could mean either:

• she is leaving the house right now
• or she leaves the house / goes out in a more general sense

But in your sentence, właśnie strongly pushes the meaning toward right now.

Compare:

• Ona wychodzi z domu o siódmej. = She leaves the house at seven.
• Ona właśnie wychodzi z domu. = She is just leaving the house now.

Yes. Polish word order is more flexible than English, though the order changes emphasis, not the basic meaning.

Your sentence:

• Ona właśnie wychodzi z domu.

Other possible versions:

• Właśnie ona wychodzi z domu. → emphasizes she in particular
• Ona wychodzi właśnie z domu. → possible, but less natural in many contexts
• Z domu właśnie wychodzi ona. → very marked, poetic, or contrastive

The most neutral and natural version here is the original one.

Not always exactly.

The Polish z is generally like z in zoo.
In z domu, it is pronounced as a voiced z sound before d.

So:

• z domu sounds roughly like z DO-moo

Also note that z can mean different things in Polish depending on context:

• with in some expressions
• from/out of in others

Here it clearly means from/out of.

A rough English-friendly guide is:

vɨ-HO-jee

More carefully:

• wy = a sound not exactly found in English; roughly between vih and vuh
• ch = like the h in Bach or Polish h/ch
• o = like o in more but shorter and cleaner
• dzi = roughly jee with a softer beginning

A more approximate pronunciation for learners:

• vih-HO-jee

And the full sentence:

• Ona właśnie wychodzi z domu.
• roughly: O-na VWASH-nye vih-HO-jee z DO-moo

You negate the verb by adding nie before it:

• Ona właśnie nie wychodzi z domu.

This means:

• She is not leaving the house right now
• or, depending on context, She isn’t going out from home right now

In Polish, nie is placed before the verb:

• wychodzi → nie wychodzi

If you wanted a more natural everyday sentence in some contexts, Polish speakers might also say:

• Ona właśnie nie wychodzi.
  if z domu is already understood.

No. That would be ungrammatical.

After z meaning from/out of, you need the genitive, so dom must change to domu.

Correct:

• z domu

Incorrect:

• z dom

This is one of the most important habits in Polish: after a preposition, always check which case it requires.