Learn Hardcore Indonesian: Saking senangnya setelah lulus ujian, dia sampai lupa membalas pesan di ponselnya. - She/He was so happy after passing the exam that she/he forgot to reply to messages on her/his phone.

saking senang-nya → “being so happy / so great was the happiness”
dia sampai lupa membalas pesan di ponselnya → “(that) he/she even forgot to reply to messages on his/her phone”

So you can think of the whole structure as:

Saking senangnya …, dia sampai lupa …
= “He/She was so happy that he/she forgot …”

Why is it senangnya and not just senang or sangat senang?

The -nya here helps turn the adjective senang (happy) into a kind of “degree” noun phrase that fits after saking.

senang = happy (plain adjective)
sangat senang = very happy
senangnya after saking = the intensity/degree of the happiness

Compare:

Dia sangat senang.
He/She is very happy. (simple description)
Saking senangnya, dia sampai lupa makan.
He/She was so happy that he/she forgot to eat.

So saking senang (without -nya) is not natural; the pattern strongly prefers or requires saking + adj + nya.

Is saking senangnya setelah lulus ujian the same as karena dia sangat senang setelah lulus ujian?

They are similar in meaning, but not identical in nuance.

Karena dia sangat senang setelah lulus ujian, dia lupa membalas pesan.
= Neutral cause-effect: “Because he/she was very happy after passing the exam, he/she forgot to reply.”
Saking senangnya setelah lulus ujian, dia sampai lupa membalas pesan.
= Emphasizes extreme degree leading to an unexpected result: “He/She was so happy after passing the exam that he/she even forgot to reply.”

Saking … usually implies:

the emotion or state was unusually strong, and
it led to a somewhat surprising or unintended consequence.

Using karena is more matter-of-fact; using saking sounds more expressive or dramatic.

What is the function of sampai in dia sampai lupa, and does it still mean “until”?

In this context sampai does not mean “until (a time)”.
Here it is used as an intensifier meaning “to the point that / even / so … that”.

dia sampai lupa ≈ “he/she even forgot” / “he/she actually forgot”

So:

Saking senangnya …, dia sampai lupa membalas pesan.
= “He/She was so happy that he/she even forgot to reply.”

This sampai is common with emotional or extreme situations:

Dia marah sampai gemetar.
He was angry to the point that he was shaking.
Dia lelah sampai tertidur di kelas.
She was so tired that she fell asleep in class.

Why is it membalas pesan and not something like menjawab pesan or membalas pesan-pesan?

A few points:

membalas pesan vs menjawab pesan
- membalas pesan literally: “to reply (give a response) to a message”
- menjawab pesan literally: “to answer a message”
Both can be understood, but membalas pesan is more idiomatic in the context of text messages / chats. It’s like “to respond to a message”.
Why not membalas pesan-pesan?
Indonesian doesn’t need plural marking the way English does.
pesan can mean “message” or “messages,” depending on context.
- membalas pesan can mean “reply to the message” or “reply to the messages.”
You might also hear:
- balas pesan (dropping the prefix, more informal)
- bales chat / bales WA (very informal, slangy; WA = WhatsApp)

What does di ponselnya literally mean, and why use di here?

Literally:

di = at / in / on (location preposition)
ponsel = mobile phone
-nya = his / her / its (possessive marker)

So di ponselnya = “on his/her phone” or “on their phone”.

Why di?

Messages exist/are located on the phone, so we say pesan di ponsel (“messages on the phone”), just like “messages on my phone” in English.

Some variations:

di HP-nya (very common; HP = “handphone,” informal)
di handphonenya / di smartphone-nya (more colloquial)
di ponsel dia (explicit “dia” instead of -nya, a bit more formal or clear)

All are understandable; di ponselnya is neutral and perfectly natural.

How do we know this sentence is talking about the past if there’s no past tense marker?

Indonesian generally does not mark tense with verb changes, unlike English.
Past, present, and future are understood from context words and world knowledge.

Here, setelah lulus ujian (“after passing the exam”) implies the action is already completed, so the whole situation is naturally understood as past:

The exam happened.
The person passed.
After that, they were so happy that they forgot to reply to messages.

If you really wanted to make it explicit, you could add time adverbs like:

kemarin (yesterday)
tadi (earlier today)
waktu itu (at that time)

But they are not grammatically necessary.

Does dia mean “he” or “she”? How do you specify gender in Indonesian?

Dia is gender-neutral. It can mean:

Indonesian pronouns usually do not encode gender. If you need to be clear about gender, you can:

Use context / names:
- Saking senangnya setelah lulus ujian, Rina sampai lupa… (clearly female from name)
- Saking senangnya setelah lulus ujian, Budi sampai lupa… (clearly male from name)
Add laki-laki (male) or perempuan (female) somewhere if really necessary:
- Seorang mahasiswa laki-laki itu saking senangnya…
- Mahasiswi itu saking senangnya… (female student)

But in most everyday Indonesian, dia remains ambiguous, and that’s considered normal.

Could we say karena terlalu senang instead of saking senangnya? What’s the difference in feel?

You can say:

Karena terlalu senang setelah lulus ujian, dia sampai lupa membalas pesan.

The difference in nuance:

saking senangnya
- More idiomatic and expressive.
- Strongly suggests: “so extremely happy that [unexpected/strong result]”.
- Often used in narrative/storytelling.
karena terlalu senang
- Slightly more literal: “because he/she was too happy”.
- Can sometimes sound like a mild criticism (e.g., “too happy” = “a bit over the top”).
- Still understandable and acceptable, but less “set phrase” than saking senangnya.

In many natural contexts, saking senangnya will sound smoother and more native-like.

Can we move setelah lulus ujian to another place in the sentence? For example:
Saking senangnya, setelah lulus ujian dia sampai lupa membalas pesan di ponselnya.

Yes, you can move setelah lulus ujian; Indonesian word order is relatively flexible for such time phrases.

Possible variations:

Original:
- Saking senangnya setelah lulus ujian, dia sampai lupa membalas pesan di ponselnya.
Time phrase in the middle:
- Saking senangnya, setelah lulus ujian dia sampai lupa membalas pesan di ponselnya.
Time phrase at the end:
- Saking senangnya, dia sampai lupa membalas pesan di ponselnya setelah lulus ujian.

All are grammatically okay, but:

The original version tightly connects senangnya with setelah lulus ujian (the happiness is specifically about passing the exam).
If you separate them too much, it can sound a bit less smooth or slightly ambiguous.

The original order is probably the most natural and clear.

Why is there no separate pronoun like “them” in membalas pesan (“reply to them”)?

In Indonesian, you usually don’t need an extra pronoun when the object is already mentioned.

membalas pesan = “to reply to (the) messages”
You don’t say membalas pesan mereka unless you really want to emphasize “their messages.”

English often uses:

“reply to them” where them = the messages / people

Indonesian typically just keeps the direct object:

Dia lupa membalas pesan di ponselnya.
= He/She forgot to reply to the messages on his/her phone.

If you want to emphasise the people more than the messages, you might rephrase:

Dia lupa membalas pesan dari teman-temannya.
He/She forgot to reply to the messages from his/her friends.

Is this sentence formal or informal, and in what contexts is it appropriate?

The sentence is in neutral, everyday standard Indonesian:

Vocabulary: saking, senang, lulus, ujian, lupa, membalas, pesan, ponsel are all standard.
No slang, no super formal words.

You can use this kind of sentence:

in spoken conversation (friends, family, colleagues)
in informal writing (texts, chats, social media)
in semi-formal writing (essays, narratives, reports, as long as the tone isn’t extremely formal)

For very formal writing, you might slightly adjust vocabulary, but this sentence is already quite acceptable in most standard contexts.