Learn Hardcore Croatian: Vi ćete doći kasnije.

It can be either. Vi is the 2nd person plural pronoun (you all), and it’s also used as a polite/formal singular form of address. So the sentence can mean either “You (sir/ma’am) will come later” or “You (all) will come later.” Use ti for one person informally.

Do Croatians normally include the subject pronoun, or can I drop "Vi"?

Pronouns are often omitted because the verb shows person/number. You can say:

Doći ćete kasnije.
Kasnije ćete doći. Keep in mind the auxiliary ćete cannot start a clause, so you can’t just say “Ćete doći kasnije.”

Why is the auxiliary "ćete" in second position?

Short forms like ću, ćeš, će, ćemo, ćete, će are clitics. Croatian places clitics in “second position” in the clause. They come right after the first stressed word/phrase:

Vi ćete doći kasnije.
Doći ćete kasnije.
Kasnije ćete doći.

Is "Vi doći ćete kasnije" okay?

No. The clitic ćete must be in second position in the clause. With Vi first, the correct order is Vi ćete doći kasnije.

How is the future tense formed in Croatian?

Future I = present of htjeti (as a clitic) + infinitive:

(Ja) ću doći
(Ti) ćeš doći
(On/ona/ono) će doći
(Mi) ćemo doći
(Vi) ćete doći
(Oni/one/ona) će doći Negation contracts with it: neću, nećeš, neće, nećemo, nećete, neće (e.g., Vi nećete doći).

Where does "ćete" come from?

It’s the 2nd person plural present of htjeti (to want), used as a future auxiliary: ću, ćeš, će, ćemo, ćete, će. In this auxiliary use it doesn’t mean “want” but just marks future.

Can I shorten the infinitive before the auxiliary (like “doć ću”)?

Not here. When the auxiliary follows the infinitive, many verbs drop the final -i (e.g., napisat ću, vidjet ću). But with -ći verbs like doći and reći, the -i stays: doći ću, reći ću. In your sentence the auxiliary comes first anyway: Vi ćete doći (no shortening). The colloquial doć’ with an apostrophe is nonstandard in careful writing.

What’s the difference between "doći" and "dolaziti"?

doći: perfective, a single, completed arrival (“to come/arrive” once).
dolaziti: imperfective, repeated or ongoing arrivals (“to be coming/used to come”). So Vi ćete doći kasnije = one arrival later; Vi ćete dolaziti kasnije = you will (regularly) come later.

Is "kasnije" the same as "poslije" or "kasno"?

kasnije = later (comparative of “kasno”), adverb: “later (than now/than expected).”
poslije = later/afterwards; also a preposition (“after”): poslije ručka = after lunch.
kasno = late (adverb/adjective): doći kasno = come late.

Can I move "kasnije" around? Does the meaning change?

Yes, time adverbs are flexible:

Vi ćete doći kasnije.
Kasnije ćete doći.
Vi ćete kasnije doći. All mean the same event; different word orders add slight emphasis (e.g., sentence-initial “Kasnije” highlights the time).

How do I say “You won’t come later”?

Vi nećete doći kasnije. You can drop the pronoun if clear: Nećete doći kasnije.

How do I ask “Will you come later?” in a neutral/formal way?

Use the full verb with the particle li:

Hoćete li doći kasnije? (formal or plural) Informally with rising intonation: Doći ćete kasnije? is also heard. The da li form (Da li ćete doći kasnije?) is common colloquially but less preferred in standard Croatian.

Can I use the present tense for near-future plans?

Yes, especially for scheduled/arranged events: Vi dolazite kasnije = “You are coming later (it’s arranged).” The future ćete doći is more neutral about plan vs prediction.

Do I have to write "Vi" with a capital V?

At the start of a sentence it’s capitalized anyway. In letters and formal emails, Croatian often capitalizes polite address forms (Vi, Vas, Vama, Vaš) as a courtesy. In ordinary text not directly addressing someone, use lowercase vi.

Any pronunciation tips for this sentence?

ć in ćete, doći is a soft “ch” (shorter/softer than English “ch”).
nj in kasnije is like “ny” in “canyon” (ka-snye-eh).
Stress is typically on the first syllable: Vì ćete dòći kàsni-je (approximate guide).

Is there any agreement or gender marking I’m missing?

Not in Future I with an infinitive. Agreement shows on ćete (2nd person plural). If you switch to past or Future II, the past participle would agree (e.g., Vi ste došli/došle depending on the group’s gender).

What about Future II (advanced): when would I use it with "doći"?

Future II (rare, mostly in subordinate clauses) is formed with present of biti + past participle: kad budete došli, javite se = “when you come, let us know.” You wouldn’t use it in a simple main clause like your sentence; there you use Future I: Vi ćete doći kasnije.