Niedawno byliśmy na szczycie.

Because the sentence talks about the past.

• jesteśmy = we are
• byliśmy = we were

So Niedawno byliśmy na szczycie uses the past tense because it means that this happened recently, not that it is happening now.

The ending -śmy shows we in the past tense.

So in byliśmy:

• byli- is the past stem of być = to be
• -śmy tells you the subject is we

That is why Polish does not need a separate word for we here. The verb already contains that information.

Polish often leaves out subject pronouns when they are already clear from the verb form.

So instead of saying My byliśmy na szczycie, Polish normally just says Byliśmy na szczycie.

• byliśmy already means we were
• adding my is possible, but it usually gives extra emphasis, like we were the ones who were there

Because after na, Polish uses different cases depending on whether you mean:

• location = being somewhere
• movement toward a place = going to somewhere

Here, byliśmy describes location: we were at the summit. So Polish uses the locative case:

• na szczycie = at/on the summit

If you wanted to say movement toward the summit, you would use:

• na szczyt = to the summit

For example:

• Byliśmy na szczycie = We were at the summit.
• Weszliśmy na szczyt = We climbed to the summit.

It is the locative singular form of szczyt.

Base form:

• szczyt = summit, peak

Locative after na for location:

• na szczycie = at the summit

The ending changes from -t to -cie here, which is a normal sound/spelling change in Polish when certain endings are added.

In the Polish past tense plural, the form can depend on gender.

• byliśmy is used for a group that includes at least one male person, or for a mixed group
• byłyśmy is used only if the group is entirely female

So if the speakers are:

• two men, or a man and a woman, or any mixed group → byliśmy
• only women → byłyśmy

This is a very common thing for English speakers to notice, because English past-tense verbs do not change this way.

Yes. Polish word order is fairly flexible, because endings carry a lot of the grammatical information.

This sentence can be rearranged, for example:

• Niedawno byliśmy na szczycie.
• Byliśmy niedawno na szczycie.
• Na szczycie byliśmy niedawno.

These all mean basically the same thing, but the emphasis changes.

• Niedawno first gives a neutral emphasis to recently
• Na szczycie first emphasizes the place
• putting byliśmy first can sound more conversational in some contexts

The original version is very natural and neutral.

Yes, niedawno usually means recently, not long ago, or a short time ago.

It is a general time word, and it does not specify exactly when. It could refer to:

• a few days ago
• a few weeks ago
• sometimes even longer, depending on context

So it is a good match for English recently or not long ago.

Not always. Literally, it means on/at the top, at the summit, or at the peak.

It can be used:

• literally, for a mountain or hill
• more generally, for the top of something
• figuratively, for being at the peak of success or power

In this sentence, without extra context, most learners will understand it as the literal idea of being at a summit or peak.

In this sentence, English would usually prefer at the summit or on the summit, depending on context.

Polish na often covers meanings that English may express with either on or at.

So na szczycie can correspond to:

• at the summit
• on the summit
• sometimes simply at the top

The exact English choice depends more on natural English style than on a strict one-to-one rule.