Przy okienku pytam, gdzie mam złożyć podpis.

Here przy okienku means at the window / at the counter, especially in an office, bank, ticket office, or other service point.

It does not usually mean a normal house window in this context. Polish often uses okienko for a service window where you speak to a clerk.

So the whole opening sets the scene: standing at the counter/window, I ask...

Because przy requires the locative case, and the locative singular of okienko is okienku.

• nominative: okienko
• locative: przy okienku

This is very common in Polish: certain prepositions force a particular case, and przy takes the locative.

Yes. Okienko is formally a diminutive of okno (window), so literally it can mean little window.

But in many real-life situations, okienko is the normal word for a service window/counter window. In places like offices or stations, it often sounds more natural than okno.

So even though it is morphologically a diminutive, here it is basically a standard word for that kind of window.

Polish usually leaves out subject pronouns when they are clear from the verb ending.

• pytam = I ask / I am asking

The ending -am already shows first person singular, so ja is unnecessary unless you want emphasis or contrast.

For example:

• Pytam... = neutral, normal
• Ja pytam... = I’m the one asking... or added emphasis

Pytam is the 1st person singular present tense of pytać (to ask).

Depending on context, it can mean:

• I ask
• I am asking

Polish present tense often covers both simple present and present continuous meanings that English separates.

So in this sentence, pytam simply means that the speaker asks the question at that moment.

Because gdzie mam złożyć podpis is a subordinate clause, and Polish normally separates subordinate clauses with a comma.

So the structure is:

• Przy okienku pytam = main clause
• gdzie mam złożyć podpis = dependent clause explaining what I ask

In English, the comma is often omitted in a sentence like I ask where I should sign, but in Polish the comma is standard.

Here mam does not mean possession, like I have a book.

In mam złożyć, the pattern mam + infinitive means something like:

• I am supposed to...
• I should...
• I need to...
• I am to...

So:

• gdzie mam złożyć podpis = where am I supposed to put/submit my signature?

This is a very common Polish structure. It often expresses obligation, instruction, or what is expected in a situation.

This is about aspect.

• złożyć = perfective
• składać = imperfective

The sentence refers to one complete act: giving/placing the signature once. Because the action is seen as a completed whole, Polish prefers the perfective złożyć.

Compare:

• Gdzie mam złożyć podpis? = Where am I supposed to sign / place my signature?
• Składać podpis would sound more like the process or repeated/habitual action, which is not what this sentence is focusing on.

So złożyć fits the idea of one finished signature action.

Podpis is in the accusative singular, because it is the direct object of złożyć.

However, podpis is a masculine inanimate noun, and in the singular, many masculine inanimate nouns have the same form in nominative and accusative.

So:

• nominative: podpis
• accusative: podpis

That is why it looks unchanged.

Yes, złożyć podpis is a normal and fairly formal expression. It means to place/submit a signature.

You could also hear other natural versions, depending on style:

• Gdzie mam się podpisać? = Where should I sign?
• Gdzie mam podpisać? = Where should I sign?
• Gdzie mam złożyć podpis? = Where should I place/provide my signature?

The version with złożyć podpis is slightly more formal or administrative.
The version with podpisać się is often more conversational.

Yes, Polish word order is more flexible than English, although not completely free.

The given sentence:

• Przy okienku pytam, gdzie mam złożyć podpis.

puts przy okienku first to set the scene: at the counter/window.

You could also say, for example:

• Pytam przy okienku, gdzie mam złożyć podpis.

This is still understandable, but it may sound slightly different in focus. The original version feels natural if you want to start with the location or situation.

So the word order here is natural, but other orders are possible depending on emphasis.