Learn Hardcore Croatian: Na kraju predstave glumci se poklone pred publikom. - At the end of the play the actors bow in front of the audience.

kraj is a noun meaning “end” or “edge”.
After the preposition na with the meaning “at (a place / a point in time)”, Croatian uses the locative case.
The locative singular of kraj is kraju.

So:

na kraj (accusative) → to the end / onto the end (movement)
na kraju (locative) → at the end (location in time or space)

In this sentence it’s about when something happens (at the end of the performance), so the locative kraju is used: Na kraju = At the end.

Why is it predstave and not predstava after Na kraju?

Predstava means “play / performance / show” and is a feminine noun.

predstava = nominative singular (“a/the play”)
predstave = genitive singular (“of the play”)

The noun kraj (“end”) normally takes the genitive to say “the end of something”:

kraj filma – the end of the film
kraj dana – the end of the day
kraj predstave – the end of the play

Because Na kraju is literally “at the end (of…)”, the next noun (predstava) must be in the genitive singular: predstave.

So:

Na kraju predstave = At the end of the play.

What is the role of glumci in the sentence, and why is it glumci and not glumce?

Glumac = “actor”, masculine.
Its nominative plural is glumci:

singular nominative: glumac – “actor”
plural nominative: glumci – “actors”

In the sentence glumci is the subject, i.e. the “doers” of the action:

Glumci se poklone… – The actors bow…

Croatian subjects are normally in the nominative case, so glumci is nominative plural.

Glumce is the accusative plural (used for direct objects), for example:

Vidim glumce. – I see the actors.

Here the actors are not being seen; they are doing the bowing, so nominative glumci is correct.

What does se do in glumci se poklone? Why is it needed?

Se is a reflexive pronoun and also part of many reflexive verbs in Croatian.

The verb pokloniti se means “to bow” (literally something like “to present oneself as a gift”).
Without se, pokloniti usually means “to give as a gift / to present (something)”.

Compare:

On mi je poklonio knjigu. – He gave me a book as a gift.
On se poklonio publici. – He bowed to the audience.

So in glumci se poklone:

se marks that the action is reflexive and changes the meaning of the verb to “bow”.
You cannot drop se here; glumci poklone pred publikom would be ungrammatical / meaningless in this context.

Why is it poklone and not something like poklanjaju or poklanjaju se?

There are two relevant verb aspects:

pokloniti (se) – perfective (“to bow once, as a complete act”)
poklanjati (se) – imperfective (“to be bowing / to bow repeatedly / habitually”)

In the sentence, we have:

poklone = 3rd person plural present tense of pokloniti (se) (perfective).

Using the perfective here emphasizes one complete, whole bow at a specific point in time: “(they) bow (once, at the end)”.

If you said:

glumci se poklanjaju pred publikom, it would suggest more the process or ongoing activity of bowing, or bowing repeatedly. In many contexts this is possible and understandable, but:
In a “script-like” description of what happens in a performance, Croatian very often uses the perfective present to list single, completed actions in sequence:
- Na kraju predstave glumci se poklone pred publikom.
  (At the end of the play, the actors bow in front of the audience.)

So poklone here is natural because it describes one completed bow in a sequence of events.

Is poklone present or future tense? How should I think about its time reference?

Morphologically, poklone is the present tense of the perfective verb pokloniti (se).

In Slavic languages (including Croatian):

Imperfective present = usually a real present, ongoing or habitual action.
Perfective present often refers to a single complete action located in the future or in a sequence.

So poklone:

Is formally present tense, but
Because the verb is perfective, it refers to a single complete event situated at a particular time (here: at the end of the play).

In English we would typically translate it with simple present in this kind of generic description:

At the end of the play, the actors bow in front of the audience.

You can also feel it a bit like “will bow” in a script or stage direction:

At the end of the play, the actors will bow in front of the audience.

Why is the word order glumci se poklone and not glumci poklone se?

In Croatian, se is a clitic (an unstressed short word) and follows a fairly strict position rule:

Clitics like se, se, si, mi, ti, mu, je, ga, ih, sam, si, je, smo, ste, su tend to appear in “second position” in the clause.

That usually means:

They come very early in the sentence, normally right after the first important word or phrase, not at the end of the verb phrase.

So:

glumci se poklone – correct and natural
glumci poklone se – wrong (the clitic se cannot stand there)

Other acceptable orders (depending on emphasis) include, for example:

Na kraju predstave glumci se poklone pred publikom.
Na kraju predstave se glumci poklone pred publikom. (also possible)

But you should avoid putting se after the full verb: poklone se at the very end of the sentence is only okay if nothing follows the verb (e.g. Glumci se poklone.). When something follows (like pred publikom), se should stay before the verb, not after it.

What does pred publikom mean exactly, and how is it different from ispred publike or pred publiku?

All of these involve the idea of being in front of the audience, but they differ in preposition and/or case.

pred publikom
- pred
  - instrumental (publikom)
- Describes location: in front of the audience (being there).
- Used here because the actors are standing in front of the audience while bowing.
pred publiku
- pred
  - accusative (publiku)
- Describes movement towards a place: to (a place) in front of the audience.
- Example:
  - On izađe pred publiku. – He comes out before the audience. (movement onto the stage, into their view)
- Not suitable in the original sentence, because the focus is on the bowing, not on moving to that position.
ispred publike
- ispred always takes genitive (publike).
- Meaning is also “in front of the audience”, but often with a little more concrete, spatial feel of “right in front of, immediately before”.
- You could say glumci se poklone ispred publike, and it would be understood; pred publikom is just a bit more neutral and idiomatic here.

So in the given sentence, pred publikom (static location, instrumental) is the most natural choice.

Which case is publikom, and why do we use that case with pred here?

Publikom is the instrumental singular of publika (“audience”).

Declension of publika (simplified):

nominative: publika – the audience
genitive: publike – of the audience
dative: publici – to the audience
accusative: publiku – (see) the audience
locative: publici – about/at the audience
instrumental: publikom – with / by / in front of the audience

The preposition pred can take:

instrumental for location (being in front of): pred publikom – in front of the audience
accusative for movement towards a position: pred publiku – in front of the audience (to that spot)

In this sentence, the actors are located in front of the audience while bowing, so we use instrumental: publikom → pred publikom.

Should there be a comma after Na kraju predstave?

Both forms are seen in real Croatian:

Na kraju predstave glumci se poklone pred publikom.
Na kraju predstave, glumci se poklone pred publikom.

Some points:

Na kraju predstave is a short time expression; Croatian often does not put a comma after such short introductory phrases.
A comma is more common after longer introductory clauses or when we want to emphasize a pause.

In standard usage, the version without the comma is very common and perfectly correct:

Na kraju predstave glumci se poklone pred publikom.

Could I say Na kraju predstave glumci se poklone publici instead of pred publikom? What’s the difference?

Yes, you can say:

Na kraju predstave glumci se poklone publici.

Here the noun publika is in the dative case (publici), and it means:

At the end of the play, the actors bow to the audience.

So:

pred publikom – literally: in front of the audience (focus on location in space).
publici (dative) – literally: to the audience (focus on to whom they bow).

Both are natural, but they emphasize slightly different things:

pred publikom paints the visual scene (actors physically in front of the audience).
publici highlights the recipient of the bow (they bow to them).

In practice, both versions are good and often interchangeable; the original sentence simply chose the “in front of” version.