Learn Hardcore Indonesian: Kakak saya berjanji menghubungi Ibu sebelum magrib. - My older sibling promised to contact Mother before sunset.

kakak laki-laki = older brother
kakak perempuan = older sister Regional alternatives you’ll hear: abang (older brother), mas (older brother, Javanese), mbak (older sister, Javanese).

Why is it kakak saya and not saya kakak for “my older sibling”?

Possession in Indonesian is typically Noun + Possessor:

kakak saya = my older sibling You can also attach the clitic -ku:
kakakku = my older sibling (more informal) Saya is the neutral/formal “I/my.” Aku/-ku is more casual.

Does Ibu here mean “my mother” even though it doesn’t say Ibu saya?

Yes. Kinship terms (Ibu, Ayah, Kakak, Adik, etc.) often omit the possessive when context makes it obvious. Capitalizing a kinship term used for a specific person also signals that it’s a title/name-like reference, so Ibu here is “Mother (mine).” If you need to be explicit, say Ibu saya or use your family’s preferred term (Mama, Bunda, etc.).

Why is Ibu capitalized?

Indonesian style capitalizes kinship terms when they refer to a specific person or are used as address forms (like a name): Ibu, Ayah, Kakak. Lowercase is used for the common noun sense (ibu = a mother, an older woman).

Do I need untuk after berjanji? Should it be berjanji untuk menghubungi?

Both are acceptable:

berjanji menghubungi Ibu …
berjanji untuk menghubungi Ibu … Including untuk sounds a bit more formal/explicit. Omitting it is very common, especially when the following verb is a meN- verb (here, menghubungi).

What about akan? Is berjanji akan menghubungi also correct? Can I say berjanji untuk akan …?

berjanji akan menghubungi is also correct; akan highlights the future aspect of the promised action.
Don’t stack them: avoid berjanji untuk akan …

There’s no past tense marking. How do I say “promised” vs “promises” vs “has promised”?

Indonesian doesn’t inflect for tense; you add time/aspect words:

Past/just now: tadi, barusan, baru saja (Kakak saya tadi berjanji …)
Completed: sudah/telah (Kakak saya sudah berjanji …)
Future: akan, nanti (Kakak saya berjanji akan …) Context often carries the time reference.

What exactly does menghubungi mean? Is it call, text, or just “contact”?

Menghubungi = “to contact (someone)” broadly (call, text, message). Alternatives:

menelepon (standard) / menelpon (common informal) = to call by phone
mengontak (informal) = to contact
mengabari = to inform/let someone know Use menghubungi when the channel doesn’t matter or isn’t specified.

Why not menghubungi kepada Ibu?

Because menghubungi is a transitive verb that takes a direct object: menghubungi Ibu. No preposition is used. You use kepada with some other verbs:

memberi kabar kepada Ibu (to give news to Mother)
berjanji kepada … (to promise to someone)

Is berjanji transitive? Can it take a direct object?

No. Berjanji doesn’t take a direct object. It takes:

a complement clause: berjanji (untuk/akan) [verb]
an indirect object with kepada for the person you promise to: berjanji kepada [person] (untuk …)

What does sebelum magrib mean exactly? When is magrib, and how is it spelled?

sebelum magrib = before magrib (the time around sunset)
In Indonesia, magrib is the common time reference for sunset/dusk (also the name/time of the Muslim sunset prayer).
Spelling: standard Indonesian uses magrib (without h). You will also see maghrib informally. Usually lowercase unless beginning a sentence or part of the prayer name (Salat Magrib).

Do I need a preposition like pada? Is sebelum pada magrib correct?

No. Use sebelum magrib without a preposition. Similarly: sesudah magrib, sebelum jam enam, etc.

Does “before magrib” modify the contacting or the promising?

In this sentence it naturally modifies the contacting: the promise is to contact Mother before magrib. If you mean the promising happened before magrib, make it explicit, e.g.:

Tadi sebelum magrib, kakak saya berjanji akan menghubungi Ibu.

How would this sound in informal speech?

Common informal variants:

Kakak janji hubungi Ibu sebelum magrib.
Abang janji telepon Ibu sebelum magrib.
Kakak janji bakal hubungi Ibu sebelum magrib. (bakal/bakalan = colloquial “will”)

Is menghubungkan correct here?

No. Menghubungkan means “to connect/link (things),” not “to contact (a person).” Use menghubungi for contacting a person, and hubungi as the imperative: Hubungi Ibu = “Contact Mom.”