W weekend lubię spacerować po centrum, zwłaszcza wieczorem.

Both forms exist in Polish, but they are used differently:

• w weekend – this is the most common, natural way to say "on/at the weekend" in everyday Polish.

  • Grammatically it’s accusative, used as an adverbial expression of time (similar to w przyszły piątek, w poniedziałek).

• w weekendzie – this form is possible but:

  • it sounds less natural in everyday speech in many contexts,
  • it tends to be used more when you are talking about a specific weekend as a period of time and describing events inside it, e.g.:
    
    • W tym weekendzie było bardzo zimno. (less common; many speakers would still prefer w ten weekend or w weekend)

For you as a learner, it's safest to use:

• w weekend = "on/at the weekend"
• w weekendy / w weekendy zwykle... = "on weekends / at weekends" (habitually)

In Polish, when you talk about liking an activity, you normally use:

lubić + infinitive

So:

• Lubię spacerować. – I like walking (as an activity).
• Lubię czytać. – I like reading.
• Lubię pływać. – I like swimming.

You can say:

• Lubię spacery. – I like walks.

…but that slightly shifts the focus toward the walks themselves (as events/things) rather than the activity in general. In many contexts, both are possible, but:

• lubię spacerować = more about the activity of walking
• lubię spacery = more about walks as countable experiences

All three can involve walking, but they feel different:

• spacerować – "to stroll", "to go for a walk"

  • relaxed, usually for pleasure, not to get somewhere specific
  • Lubię spacerować po centrum. – I like strolling around the center.

• chodzić – "to walk (habitually)", "to go (repeatedly / in general)"

  • can be about walking, but also about going somewhere regularly
  • Chodzę do pracy pieszo. – I walk to work.
  • Lubię chodzić po mieście. – I like walking around the city. (more general than spacerować)

• iść – "to go (on foot) right now / at this moment / in one specific direction"

  • one-time, concrete movement
  • Idę do sklepu. – I’m going to the shop (on foot, now).

In the sentence:

W weekend lubię spacerować po centrum…

spacerować is ideal because it suggests relaxed, aimless walking for pleasure, which matches the idea of weekend evening strolls.

Both are correct, but they emphasize different ideas:

• w centrum = in the center (inside that area)

  • Focus on location: where something happens.
  • Mieszkam w centrum. – I live in the center.

• po centrum (with po

  • locative) = around / through the center, moving around inside that area
  • Focus on movement within the center.
  • Spacerować po centrum – to walk around the center (through different streets, not just standing or sitting there).

So:

spacerować po centrum = walk around the city center, moving through it
spacerować w centrum = walk in the center (grammatically OK, but less idiomatic here; po centrum is the very natural collocation)

In po centrum, the noun centrum is in the locative case.

The general rule for po is:

• po + locative when it means movement or distribution within / over / around a surface or area:
  • po centrum – around/through the center
  • po parku – around the park
  • po ulicy – along the street
  • po całym domu – all over the house

So:

• po + [locative] – movement within/over an area, or distribution over it
• w + [locative or accusative], na + [locative or accusative] – similar patterns, but with different meanings

In this sentence:

• po → requires locative
• centrum → has locative form (w/po) centrum (same as nominative for this neuter noun)

zwłaszcza means especially / in particular. It highlights something as a special case out of a broader group.

• W weekend lubię spacerować po centrum, zwłaszcza wieczorem.
  → On weekends I like walking around the center, especially in the evening.

szczególnie is very similar and often interchangeable:

• W weekend lubię spacerować po centrum, szczególnie wieczorem.

Nuance:

• In everyday speech, many people use them almost synonymously.
• Some speakers feel:
  • zwłaszcza = a bit stronger "especially, above all"
  • szczególnie = "particularly, in a special way", sometimes more about degree (how much) than selection.

But in most learner contexts, you can treat them as near-synonyms and both are fine here.

wieczór is the basic noun (evening), and wieczorem is its instrumental form, used adverbially to mean "in the evening".

Polish very often uses instrumental for time expressions like this:

• rano (from ranek) – in the morning
• wieczorem (from wieczór) – in the evening
• nocą (from noc) – at night
• latem (from lato) – in summer

So:

• Wieczorem oglądam film. – I watch a film in the evening.
• You usually do not say w wieczór in this time sense. It sounds wrong/unnatural.

In your sentence:

…zwłaszcza wieczorem.
= especially in the evening (using the instrumental as an adverbial time expression).

Yes, you can change the word order; Polish word order is relatively flexible.

Possible variants:

• W weekend lubię spacerować po centrum, zwłaszcza wieczorem.
  – Neutral, natural; first sets the time, then what you like.

• Lubię spacerować po centrum w weekend, zwłaszcza wieczorem.
  – Also correct; starting with lubię emphasizes the liking a bit more.

• Lubię w weekend spacerować po centrum, zwłaszcza wieczorem.
  – Also possible; slightly more spoken-style, stressing weekend as the time when you like doing it.

The basic meaning stays the same: the differences are in emphasis and rhythm, not in facts.

The part zwłaszcza wieczorem is an adverbial phrase of exception/emphasis; it adds extra, non-essential information ("in particular, in the evening"). In Polish, such additional modifying phrases are often set off by a comma.

Think of it like an English comma before "especially in the evening":

• I like walking around the center at the weekend, especially in the evening.

So:

• Main statement: W weekend lubię spacerować po centrum.
• Extra emphasis: zwłaszcza wieczorem.

The comma marks that second part as an additional, emphatic detail.

To express a general habit on weekends, Polish often uses a plural time expression:

• W weekendy lubię spacerować po centrum, zwłaszcza wieczorami.

Breakdown:

• w weekendy – on weekends / at weekends (regularly)
• wieczorami – in the evenings (habitually, plural form used adverbially)

So the original sentence:

• W weekend lubię spacerować po centrum, zwłaszcza wieczorem.
  – feels more like "On a / the weekend…" (single weekend, or a typical one).

The habitual/general version:

• W weekendy lubię spacerować po centrum, zwłaszcza wieczorami.