Nie chcę dziś rozmawiać z nikim o pracy.

Because Polish normally uses double negation.

In English, you usually say I don’t want to talk to anyone.
In Polish, when the verb is negative, words like anyone / nothing / nowhere / never also become negative:

• nie = not
• nikt = nobody
• nic = nothing
• nigdy = never
• nigdzie = nowhere

So:

• Nie chcę rozmawiać z nikim = I don’t want to talk to anybody / anyone

Using kimś here would sound wrong in standard Polish, because after nie chcę, Polish expects nikim, not kimś.

Because nikt changes form depending on its grammatical role in the sentence.

The basic dictionary form is nikt = nobody.
But after the preposition z meaning with, Polish uses the instrumental case.

So:

• nikt = base form
• z nikim = with nobody / with anyone

That is why the sentence has:

• z nikim = with no one

Nikim is in the instrumental case.

The reason is simple: the preposition z in the meaning with requires the instrumental.

Examples:

• z bratem = with my brother
• z koleżanką = with a female friend
• z kimś = with someone
• z nikim = with no one

So in rozmawiać z nikim, the form nikim is there because of z.

Because the preposition o meaning about requires the locative case.

The noun praca changes like this:

• praca = nominative
• pracę = accusative
• pracy = locative/genitive form here

So:

• o pracy = about work

Compare:

• Myślę o pracy = I’m thinking about work
• Rozmawiamy o pracy = We’re talking about work

In Polish, the subject pronoun is often omitted because the verb ending already shows who is doing the action.

Here:

• chcę = I want

So ja is not necessary.

You could say:

• Ja nie chcę dziś rozmawiać z nikim o pracy

But that sounds more emphatic, as if you are stressing I in particular.

In normal speech, Polish usually leaves ja out unless it is needed for contrast or emphasis.

Because after chcę = I want, Polish usually uses an infinitive, just like English does after want to.

So:

• chcę rozmawiać = I want to talk

Other similar examples:

• Chcę odpocząć = I want to rest
• Chcę iść do domu = I want to go home
• Nie chcę czekać = I don’t want to wait

So the structure is:

• chcę + infinitive

Polish word order is more flexible than English word order. The sentence you have is very natural, but other orders are also possible.

The original:

• Nie chcę dziś rozmawiać z nikim o pracy.

This feels neutral and natural:
I don’t want to talk with anyone about work today.

You could also hear:

• Dziś nie chcę rozmawiać z nikim o pracy.
• Nie chcę z nikim dziś rozmawiać o pracy.
• Nie chcę dziś z nikim rozmawiać o pracy.

These all mean basically the same thing, but the emphasis shifts a little depending on what comes earlier.

A useful general rule: in Polish, moving a word often changes focus more than basic meaning.

They both mean today.

• dziś = today
• dzisiaj = today

In most situations, they are interchangeable.
Dziś is a bit shorter and sometimes feels slightly more concise or stylistically lighter, but both are completely normal.

So these are both fine:

• Nie chcę dziś rozmawiać z nikim o pracy.
• Nie chcę dzisiaj rozmawiać z nikim o pracy.

Rozmawiać means to talk / to have a conversation.
It suggests interaction between people.

Mówić means to speak / to say / to talk, but it is broader and not always conversational in the same way.

So:

• rozmawiać z kimś = talk with someone
• mówić o czymś = speak/talk about something

In this sentence, rozmawiać is the most natural choice because the idea is having a conversation with someone.

So:

• Nie chcę dziś rozmawiać z nikim o pracy
  sounds more natural than
• Nie chcę dziś mówić z nikim o pracy

In fact, mówić z kimś is much less common than rozmawiać z kimś.

This is about aspect, which is very important in Polish.

• rozmawiać = imperfective
• porozmawiać = perfective

Very roughly:

• rozmawiać focuses on the activity/process of talking
• porozmawiać often means to have a talk / to talk for a bit / to complete the conversation as one event

In this sentence, rozmawiać is very natural because the speaker is talking generally about not wanting to engage in that activity today.

• Nie chcę dziś rozmawiać z nikim o pracy.
  = I don’t want to talk with anyone about work today.

You could also hear:

• Nie chcę dziś porozmawiać z nikim o pracy.

But that would sound a bit different, more like I don’t want to have a conversation with anyone about work today as a single completed event. The imperfective version is the more neutral one here.

Yes. That is very natural in Polish.

For example:

• Nie chcę dziś rozmawiać z nikim o pracy.
• Nie chcę dziś z nikim rozmawiać o pracy.

Both are correct.

The second version is often especially natural because z nikim rozmawiać stays together as a unit: to talk with no one / with nobody.

Polish often allows this kind of movement more freely than English.

It can mean either, depending on context.

• praca can mean work in a general sense
• it can also mean one’s job / work situation

So o pracy may mean:

• about work in general
• about my work
• about your work
• about someone’s job

The surrounding context tells you which one is meant.

A rough breakdown is:

• Nie = not
• chcę = I want
• dziś = today
• rozmawiać = to talk
• z nikim = with nobody / with anyone
• o pracy = about work

So very literally:

• Not want-I today to-talk with nobody about work

But the natural English meaning is:

• I don’t want to talk to anyone about work today.

Chcę is the 1st person singular form of chcieć = to want.

It means:

• I want

The letter ę is a nasal vowel. In careful pronunciation, it is nasalized, though in normal speech the exact sound can vary depending on what comes next.

You do not need to memorize all pronunciation details right away; the most important thing is to recognize that:

• chcę = I want
• chcesz = you want
• chce = he/she/it wants

So even if the pronunciation feels tricky at first, the form itself is very common and worth learning early.