Na tym placu zabaw zawsze jest dużo dzieci, ale i tak przyjemnie się tam spaceruje.

Because na can mean on / at when talking about location, and after na in a location sense, Polish uses the locative case.

• ten plac zabaw = this playground
• locative: na tym placu zabaw = at/on this playground

Only the main noun changes here:

• plac → placu
• tym is the locative form of ten
• zabaw stays the same because plac zabaw is a fixed expression, literally something like a place of play

So the whole phrase means at this playground.

After quantity words like dużo meaning a lot of, Polish normally uses the genitive.

So:

• dużo dzieci = a lot of children
• not dużo dzieciom, dużo dzieciach, etc.

A useful pattern:

• dużo ludzi = a lot of people
• mało czasu = little time
• wiele książek = many books
• trochę wody = a little water

In this sentence, dzieci happens to look the same in both nominative plural and genitive plural, so you do not see a form change. But grammatically, after dużo, it is genitive.

This is a very common question. In Polish, when the subject is really a quantity expression like dużo dzieci, the verb is often singular:

• jest dużo dzieci
• było dużo ludzi
• będzie wiele problemów

That is because Polish treats expressions like dużo dzieci more like there is a lot of children / there is a large number of children than like a simple plural subject.

So:

• Na tym placu zabaw zawsze jest dużo dzieci = There are always a lot of children at this playground

Using jest is standard and natural here.

Ale i tak means something like:

• but still
• but even so
• but anyway

It introduces a contrast: something might seem inconvenient or negative, but the following statement remains true.

Here:

• zawsze jest dużo dzieci = there are always lots of children
• ale i tak przyjemnie się tam spaceruje = but it is still pleasant to walk there

So the idea is: Even though there are always many children there, it is still pleasant to walk there.

This is an impersonal construction with się.

Literally, Polish is not saying someone walks there pleasantly. Instead, it uses a general, subjectless expression:

• spaceruje się = one walks / people walk / it is possible/natural to walk
• przyjemnie się spaceruje = it is pleasant to walk
• przyjemnie się tam spaceruje = it is pleasant to walk there

The się here does not really mean oneself. It helps create an impersonal meaning, very common in Polish.

Other examples:

• Tu dobrze się pracuje. = It is good to work here.
• W tym mieście świetnie się mieszka. = It is great to live in this city.
• Latem długo się siedzi na dworze. = In summer, people sit outside for a long time.

Because przyjemnie is an adverb, while przyjemny is an adjective.

In this sentence, Polish is describing how it is to walk there, not describing a noun. That is why it uses the adverb:

• przyjemnie = pleasantly / pleasantly enough / pleasantly so / in a pleasant way
• przyjemny = pleasant, but used with a noun, for example:
  • przyjemny spacer = a pleasant walk
  • przyjemne miejsce = a pleasant place

So:

• Przyjemnie się tam spaceruje = It is pleasant to walk there
• not Przyjemny się tam spaceruje

Tam means there, and it refers back to the playground.

It is not absolutely necessary, but it sounds natural. It helps keep the place in focus and makes the second half of the sentence flow nicely.

Compare:

• ...ale i tak przyjemnie się tam spaceruje. = ...but it is still pleasant to walk there.
• ...ale i tak przyjemnie się spaceruje. = ...but it is still pleasant to walk.

The version with tam is slightly more explicit and connected to the first part of the sentence.

Zawsze means always, and in this sentence it naturally modifies the whole statement jest dużo dzieci.

So:

• Na tym placu zabaw zawsze jest dużo dzieci = At this playground there are always a lot of children

This word order is very natural in Polish. It presents the location first, then the time-frequency idea, then the existence statement.

You could rearrange the words, but the emphasis would change. For example:

• Na tym placu zabaw jest zawsze dużo dzieci
• Dużo dzieci zawsze jest na tym placu zabaw

These are possible, but the original sounds the most neutral and natural.

No. Here it expresses a general, habitual idea, not something happening at this exact moment.

Because the sentence also contains zawsze and describes a general situation, the present tense has a broad meaning:

• zawsze jest dużo dzieci = there are always lots of children
• przyjemnie się tam spaceruje = it is pleasant to walk there, generally speaking

So the whole sentence is about a regular characteristic of the place, not one specific moment.

Not exactly. Spacerować usually means:

• to stroll
• to go for a walk
• to walk around leisurely

It often suggests walking for pleasure rather than just moving from one place to another.

So here:

• przyjemnie się tam spaceruje is closer to it is pleasant to stroll there or it is nice to go for a walk there

If the sentence used a verb meaning simple movement on foot, the nuance would be different. Spacerować fits well with przyjemnie because it suggests a pleasant, leisurely walk.