Dziś nocuję w hotelu obok parku.

Both dziś and dzisiaj mean today. In most cases, they are interchangeable.

• dziś – slightly shorter, a bit more colloquial or stylistically lighter
• dzisiaj – slightly more neutral and common in everyday speech

In this sentence, you could also say:

• Dzisiaj nocuję w hotelu obok parku.

No change in meaning.

Literally, dziś means today, but because the verb nocuję is about spending the night, the whole sentence is naturally understood as tonight I’m staying overnight.

Context makes it clear that the action happens during the night of today. So dziś can cover what in English might be expressed as tonight when the verb itself implies night-time.

These verbs focus on slightly different things:

• nocować → nocuję: to spend the night somewhere, to stay overnight (typical for hotels, hostels, etc.)
• spać → śpię: to sleep (emphasis on the act of sleeping, not on accommodation)
• zostawać → zostaję: to stay/remain (very general, not necessarily overnight or in accommodation)

Dziś nocuję w hotelu… focuses on the idea that your place of overnight stay today is a hotel next to the park.
You could say:

• Dziś śpię w hotelu… – understandable, but feels more like “I’m sleeping in a hotel” (less standard for talking about accommodation).
• Dziś zostaję w hotelu… – could work, but sounds more like “I’m staying (not going anywhere else) in the hotel today,” not specifically about one night’s lodging.

Nocować is a verb of the -ować type. In the present tense its stem changes and you get -uję in the first person singular:

Present tense of nocować:

• ja nocuję – I stay overnight
• ty nocujesz – you (sg.) stay overnight
• on/ona/ono nocuje – he/she/it stays overnight
• my nocujemy – we stay overnight
• wy nocujecie – you (pl.) stay overnight
• oni/one nocują – they stay overnight

So nocuję is exactly the regular first person singular present tense form: I am staying overnight.

The preposition w (in) with a static location (where something/someone is) requires the locative case.

• hotel (nominative, dictionary form)
• w hotelu (locative, used after w for location)

Compare:

• Mieszkam w Warszawie. – I live in Warsaw. (locative)
• Jestem w domu. – I’m at home. (locative)

So w hotelu means in the hotel / at the hotel as a place where you are staying, not a direction.

• w hotelu = in/at the hotel (location, where you are)
• do hotelu = to the hotel (direction, where you are going)

Examples:

• Dziś nocuję w hotelu obok parku. – Tonight I’m staying in a hotel next to the park. (location)
• Idę do hotelu obok parku. – I’m going to the hotel next to the park. (direction)

So the choice depends on whether you’re talking about being somewhere or going somewhere.

The preposition obok (next to, beside) always takes the genitive case.

• park (nominative)
• parku (genitive)

So:

• obok parku – next to the park

Other prepositions that also require the genitive include koło (near), blisko (close to), naprzeciw (opposite), etc.

parkiem would be instrumental (used with prepositions like z – with, or to describe tools/means), so it would be wrong here.

All three can mean something like near/next to the park, but there are nuances:

• obok parku – right next to the park, beside it (neutral, very common).
• koło parku – near the park; often interchangeable with obok, slightly more colloquial in some regions.
• przy parku – by the park, at the edge/side of the park, suggests being directly adjacent and somewhat “attached” to it (like a building by a park).

In most everyday conversations, obok parku and koło parku will sound almost the same to learners in meaning.

Yes. Polish word order is relatively flexible. All of the following are possible and natural:

• Dziś nocuję w hotelu obok parku.
• Nocuję dziś w hotelu obok parku.
• W hotelu obok parku dziś nocuję. (more marked/emphatic)

The differences are mostly in emphasis and rhythm, not in core meaning.
Putting dziś at the beginning is very natural; putting it after the verb is also fine.

Polish has no articles (no direct equivalent of a/an/the).
The phrase w hotelu by itself can mean:

• in a hotel
• in the hotel

Context (and sometimes word choice) decides:

• Dziś nocuję w hotelu obok parku. – Usually understood as some hotel next to the park.
• Dziś nocuję w tym hotelu obok parku. – tym explicitly marks that hotel next to the park.

So, w hotelu is neutral, and you interpret it as a or the based on the situation.

Key points:

• dziś – sounds roughly like jish in English (the d is almost merged with zi):
  • dzi ≈ like ji in jeans
  • ś – soft sh, tongue closer to the palate than in English sh
• nocuję – no-TSOO-ye:
  • c = ts (like cats)
  • uję – oo-ye
• w – usually pronounced like English v.
• hotelu – ho-TEH-loo, stress always on the second-to-last syllable: ho-TE-lu.
• obok – O-bok, stress on O.
• parku – PAR-koo, stress on PAR.

Remember: in Polish, stress is almost always on the penultimate (second-to-last) syllable.

In this form and with dziś, nocuję is clearly about tonight (today) – a concrete, current situation.

But in general, the present tense in Polish can express:

• Right now / today:
  Dziś nocuję w hotelu. – Tonight I’m staying at a hotel.
• Habit / repeated action (with adverbs of frequency):
  Często nocuję w hotelach. – I often stay in hotels.

So context and adverbs (like dziś, często, zwykle) decide whether it’s one-time or habitual.