Learn Hardcore Indonesian: Pagi itu pemimpin gereja menyampaikan pengumuman resmi di gereja. - That morning the church leader delivered an official announcement at the church.

pagi itu refers to a specific morning that both speaker and listener know about (already mentioned in the story, or clear from context).
Without itu, pagi would sound more like a/one morning in a general or unspecific sense.

Compare:

pagi ini = this morning
pagi itu = that (particular) morning

Could I also say pada pagi itu or di pagi itu instead of pagi itu?

pada pagi itu is grammatically correct and slightly more formal or written. It emphasises the time expression, like saying on that morning.
di pagi itu is much less common and usually avoided; di is more natural for places, not times.

In everyday Indonesian, pagi itu (without any preposition) is completely natural and probably the most common form in a sentence like this.

How do we know this sentence is talking about the past if the verb isn’t changed?

Indonesian verbs do not change form for past, present, or future.

Time is shown mainly by:

time words: pagi itu (that morning), kemarin (yesterday), besok (tomorrow), etc.
sometimes by context or extra markers like sudah / telah (already).

In this sentence:

pagi itu clearly puts the action in the past. You could say Pagi itu pemimpin gereja sudah menyampaikan… to emphasise that it had already happened, but it’s not required.

What exactly is the verb here, and can I replace menyampaikan with other verbs?

The main verb is menyampaikan.

Possible replacements (with slightly different nuances):

menyampaikan pengumuman
= to deliver / convey an announcement (neutral, slightly formal).
memberikan pengumuman
Literally to give an announcement. Understandable and grammatical, but less idiomatic than menyampaikan pengumuman.
mengumumkan
This verb already contains the idea “to announce”, so you normally don’t add pengumuman:
- Pagi itu pemimpin gereja mengumumkan keputusan resmi di gereja.

Using menyampaikan pengumuman is very natural and common, especially in formal or semi-formal settings.

How is menyampaikan formed, and what does this pattern mean?

Base word: sampai (to arrive, to reach).
Derived verb: menyampaikan.

Formation:

Prefix meN-
- root sampai
  - suffix -kan
meN-
- sampai → menyampai- (the p changes to y because of a standard spelling rule)
- -kan → menyampaikan

Meaning:

With this pattern, menyampaikan means to cause something to reach someone, i.e. to convey, to deliver (a message, information, announcement).

Examples:

menyampaikan pesan = to deliver a message
menyampaikan keluhan = to convey a complaint

Why is it menyampaikan and not mensampaikan or just menyampai?

Two main reasons:

Spelling rule for meN- prefix
- With roots starting with p, the prefix meN- causes p to drop and m or another consonant to appear.
- meN-
  - sampai becomes menyampai-, not mensampai-.
The verb needs -kan
- sampai by itself is like arrive/reach.
- Adding -kan turns it into a causative: to make something reach (someone) → to convey/deliver.
- So the full form menyampaikan is required for the meaning to deliver/convey.

There is no standard verb menyampai in this sense; the natural form is menyampaikan.

Why is gereja repeated twice? Is that normal?

Yes, it’s normal and not wrong:

pemimpin gereja = the church leader (a leader of a church or of the church in general).
di gereja = at church (the physical location).

The first gereja is part of a noun phrase describing the person’s role.
The second gereja tells you where the announcement was delivered.

In context, you could often drop the last di gereja if it’s obvious where the announcement was made:

Pagi itu pemimpin gereja menyampaikan pengumuman resmi.
(Still a complete and natural sentence if the location is already known.)

Could pemimpin gereja be replaced by pendeta or pastor? Do they mean the same?

They overlap, but are not identical:

pemimpin gereja
Literally church leader. Very general; could be a pastor, a priest, an elder, a church board leader, etc. It focuses on the role as a leader.
pendeta
Commonly pastor or minister (especially in Protestant contexts). It’s a specific religious title.
pastor
Used, for example, for Catholic priests (from English/Latin “pastor”), and sometimes for Protestant pastors too, depending on denomination.

So:

If you know the person is specifically a pastor:
Pagi itu pendeta menyampaikan pengumuman resmi di gereja.
If you just want a neutral term for “the leader of the church”: pemimpin gereja is fine.

Why is there no word for “the” or “a” in pemimpin gereja and gereja?

Indonesian usually has no articles like a/an or the.

pemimpin gereja can mean the church leader or a church leader, depending on context.
di gereja can mean at the church or at a church.

If you really want to emphasise “a” (one, not specific), you can add seorang (for people) or sebuah (for things/buildings):

Pagi itu seorang pemimpin gereja menyampaikan… = That morning, a (certain) church leader delivered…
di sebuah gereja = at a (certain) church

But in most cases, plain pemimpin gereja and di gereja are natural and sufficient.

What is the role of di in di gereja? Could we use ke instead?

di = at / in / on (location, where something is).
- di gereja = at church (location of the action).
ke = to / towards (direction, movement to a place).
- ke gereja = to the church (movement in that direction).

In this sentence, the action (delivering the announcement) happens at the church, not towards it, so di gereja is correct.

Compare:

Pagi itu pemimpin gereja pergi ke gereja.
That morning the church leader went to church. (movement)
Pagi itu pemimpin gereja menyampaikan pengumuman resmi di gereja.
That morning the church leader delivered an official announcement at church. (location)

What does pengumuman resmi mean exactly, and why is the order “pengumuman” then “resmi”?

pengumuman = announcement, notice.
resmi = official (formal, from an authority).

So pengumuman resmi = an official announcement.

Word order:

In Indonesian, the typical order is noun + adjective:
- pengumuman resmi = official announcement
- rumah besar = big house
- keputusan penting = important decision

Putting resmi before pengumuman (resmi pengumuman) is not normal Indonesian grammar for this meaning.

Is pengumuman related to any verb? How would I say “to announce”?

Yes. The noun pengumuman (announcement) is related to the verb mengumumkan (to announce).

Base: umum (public, general)
Verb: mengumumkan = to make something public → to announce
Noun: pengumuman = the act/result of announcing → announcement

Examples:

Pagi itu pemimpin gereja mengumumkan keputusan penting.
That morning the church leader announced an important decision.
Pagi itu pemimpin gereja menyampaikan pengumuman resmi.
That morning the church leader delivered an official announcement.

Both are correct; the first focuses on the act of announcing, the second on delivering the announcement.

Can this sentence be shortened or made more casual in everyday speech?

Yes. A few natural, slightly less formal variants:

Drop resmi if the “official” nuance isn’t important:
- Pagi itu pemimpin gereja menyampaikan pengumuman di gereja.
Drop the final di gereja if the setting (in church) is already obvious:
- Pagi itu pemimpin gereja menyampaikan pengumuman resmi.
Use pendeta if the leader is specifically a pastor:
- Pagi itu pendeta menyampaikan pengumuman resmi.

The original sentence is correct and slightly formal; these are just style options.