Learn Hardcore Indonesian: Kami bertemu Senin pagi di perpustakaan. - We meet on Monday morning at the library.

kami = we (excluding the listener). Use it when the person you’re talking to is not part of the group that met.
kita = we (including the listener). Use it when you’re including the person you’re talking to. If you are inviting the listener, say Kita bertemu Senin pagi di perpustakaan. If you’re just reporting what your group did/does, use kami.

Do I need to add hari or pada before Senin pagi?

Not required. Senin pagi is perfectly natural. More formal options:

hari Senin (e.g., pada hari Senin pagi) adds explicit “day.”
pada Senin pagi is also fine in formal writing. In everyday speech, most people just say Senin pagi.

Is the word order fixed? Where do time and place normally go?

Indonesian is flexible. Common, natural options include:

Time first: Senin pagi, kami bertemu di perpustakaan.
Subject–Verb–Time–Place: Kami bertemu Senin pagi di perpustakaan.
Subject–Verb–Place–Time: Kami bertemu di perpustakaan Senin pagi. All are acceptable; fronting time adds emphasis on when. Keep the unit Senin pagi together.

Should Senin be capitalized?

Yes. Day names are capitalized: Senin, Selasa, Rabu, Kamis, Jumat, Sabtu, Minggu. The part of the day (pagi/siang/sore/malam) is not capitalized unless at the start of a sentence.

Does bertemu need dengan (as in “meet with”)?

Bertemu can stand alone: Kami bertemu…
To name whom you meet, add dengan: Kami bertemu dengan Andi. Colloquially some people drop dengan (e.g., bertemu Andi), but the standard form is bertemu dengan [person]. Alternatively, use transitive menemui: Kami menemui Andi.

What’s the difference between bertemu, ketemu, menemui, and (ber)jumpa?

bertemu: standard “to meet (each other).”
ketemu: informal/colloquial for “meet/find”; common in speech.
menemui [orang]: transitive “to go meet/see someone.”
berjumpa/jumpa: somewhat formal or regional; common in Malaysia; understood in Indonesia. Nouns: pertemuan (a meeting/event), rapat (a business/committee meeting).

How do I make it clearly past or future? Indonesian has no tense, right?

Correct—use time words/particles:

Past: add sudah or a past time phrase. Example: Kami sudah bertemu pada Senin pagi (minggu lalu) di perpustakaan.
Future: add akan or a future time phrase. Example: Kami akan bertemu pada Senin pagi (minggu depan) di perpustakaan. Time phrases like kemarin, minggu lalu, minggu depan, nanti, tadi also help.

Why di perpustakaan and not ke perpustakaan?

di = at/in (location): Kami bertemu di perpustakaan.
ke = to/toward (movement): Kami pergi ke perpustakaan. Use di for where something happens, ke for where you go.

Does Indonesian have “the” or “a”? How do I say “the library”?

Indonesian has no articles. perpustakaan can be “a library” or “the library,” depending on context. To make it definite, add itu or a modifier:

di perpustakaan itu = at that/the (already known) library
di perpustakaan kampus = at the campus library

Can I front the time and add a comma, like “Senin pagi, kami …”?

Yes. Fronting time is common. A comma after a fronted time phrase is optional in casual writing and recommended in formal writing:

Senin pagi, kami bertemu di perpustakaan.

Can I omit the subject and just write a note like “Meet Monday morning at the library”?

Yes, in notes or messages it’s natural to drop the subject:

Bertemu Senin pagi di perpustakaan. In full sentences, keep kami/kita.

Is pagi Senin okay, or should it be Senin pagi?

The idiomatic order is Senin pagi. You may see pagi hari Senin in more formal contexts, but plain pagi Senin is uncommon and can sound off. Prefer Senin pagi (or formally pada pagi hari Senin).

How do I add the person we’re meeting?

Use either:

bertemu dengan [nama]: Kami bertemu dengan Andi Senin pagi di perpustakaan.
menemui [nama]: Kami menemui Andi Senin pagi di perpustakaan.

What are the typical parts of the day I can use like pagi?

pagi (morning)
siang (midday/early afternoon)
sore (late afternoon/early evening)
malam (night)
dini hari (pre-dawn) Combine with days: Senin sore, Selasa malam, etc.

How would I ask “When/Where do we meet?” in Indonesian?

When: Kapan kita bertemu? or Kita bertemu kapan?
Where: Di mana kita bertemu? To ask the time of day: Jam berapa/pukul berapa kita bertemu?

How do you pronounce perpustakaan and bertemu?

perpustakaan: per-pus-ta-KA-an. The r is tapped; u like “oo” in “book,” final -an is a light syllable. Stress tends toward the second-to-last full syllable (ka).
bertemu: bər-TE-mu. The first e is a schwa (like the ‘a’ in “about”).
Senin: sə-NIN (first e is a schwa).
kami: KAH-mi (short, unaspirated consonants).

Why is di written separately here? I’ve seen di- attached to words too.

di (separate) is a preposition meaning “at/in”: di perpustakaan.
di- (attached) is a passive verb prefix: dibaca (is/was read). So use spaced di for locations, attached di- for passive verbs.