Learn Hardcore Indonesian: Saking lelahnya setelah lembur, saya sampai lupa menyalakan alarm ponsel. - I was so tired after working overtime that I forgot to turn on my phone alarm.

“Saking lelahnya” is a structure that means “so tired (to such an extent)” and it normally implies a result, often followed by “sampai …” (so tired that…).

Saking lelahnya: emphasizes the degree of tiredness that it causes some consequence.
- Saking lelahnya setelah lembur, saya sampai lupa…
  → I was so tired after working overtime that I even forgot…
Sangat lelah: just means very tired, with no built‑in idea of a result.
- Saya sangat lelah setelah lembur.
  → I was very tired after working overtime.

You can rewrite the sentence more neutrally as:
Karena saya sangat lelah setelah lembur, saya lupa menyalakan alarm ponsel.
It’s correct, but it loses the strong “so … that …” flavor of saking … sampai ….

What is the function of “-nya” in “lelahnya” here? Is it “his/her tiredness”?

In “saking lelahnya”, the -nya does not mean “his/her” in a normal possessive sense. Instead, it is:

a grammatical marker that helps turn the adjective lelah (tired) into something more like “the tiredness”, and
it makes the expression sound natural and idiomatic in the structure saking + adj-nya.

So:

lelah = tired
lelahnya in this pattern = “the level of tiredness” / “how tired (someone is)”

You normally say:

saking capeknya (so tired)
saking marahnya (so angry)
saking laparnya (so hungry)

If you omit -nya here (saking lelah), it will sound wrong or at least very unnatural.

What does “lembur” mean exactly? Is it a noun or a verb, and how is it used?

“Lembur” refers to overtime work—working longer hours than usual, typically at your job.

It’s flexible in word class in everyday Indonesian:

As a verb-like usage:
- Hari ini saya harus lembur.
  → Today I have to work overtime.
As a noun-like usage:
- Setelah lembur, saya langsung pulang.
  → After (the) overtime, I went straight home.

In your sentence:

setelah lembur is understood as “after working overtime”,
not about overtime pay or anything like that.

What does “sampai” mean in “saya sampai lupa menyalakan alarm ponsel”? Is it “until”?

Normally, sampai can mean “until” (time) or “up to (a place)”.
But in this structure, sampai means something like:

“to the point that…”
“so (X) that I even…”

So:

Saking lelahnya …, saya sampai lupa menyalakan alarm ponsel.
→ I was so tired … that I (even) forgot to turn on my phone alarm.

Other similar uses:

Dia kaget sampai jatuh.
→ He was so shocked that he fell down.

Here, sampai is not about time; it’s an intensifier expressing the resulting extent of something.

Is “saking … sampai …” a fixed pattern in Indonesian? Can I use it with other adjectives?

Yes, “saking … sampai …” is a productive and common pattern:

saking + adjective(-nya) + clause with sampai …

Meaning: “so (adjective) that …”.

Examples:

Saking laparnya, dia sampai makan tiga porsi.
→ He was so hungry that he ate three portions.
Saking malunya, dia sampai tidak berani keluar kamar.
→ She was so embarrassed that she didn’t dare leave her room.
Saking dinginnya, air di luar sampai membeku.
→ It was so cold that the water outside froze.

So your sentence follows a very normal pattern:

Saking lelahnya (setelah lembur), saya sampai lupa …
→ So tired … that I forgot …

Could I just say “Karena saya sangat lelah setelah lembur, saya lupa menyalakan alarm ponsel” instead? What’s the nuance difference?

Yes, that sentence is grammatically correct and natural:

Karena saya sangat lelah setelah lembur, saya lupa menyalakan alarm ponsel.
→ Because I was very tired after working overtime, I forgot to turn on my phone alarm.

Nuance difference:

Karena saya sangat lelah…
- Focuses on the cause (because I was very tired).
- More neutral, straightforward.
Saking lelahnya…, saya sampai lupa…
- Emphasizes the extreme degree of tiredness and its surprising result.
- Feels more expressive, like “I was so tired that I even forgot…”.

Both are fine; saking … sampai … adds more emotional or dramatic flavor.

Why is it “menyalakan alarm ponsel”? Could I say “menghidupkan” or “setel alarm” instead?

Menyalakan literally means “to turn on” (to switch on, often related to something that gives light or starts working).
Here it’s used more broadly as “to turn on/activate” the phone alarm.

Alternatives:

Menghidupkan alarm ponsel
- Literally “to give life to / turn on” the phone alarm.
- Also acceptable, though menyalakan is more common for devices and alarms.
Menyetel / setel alarm ponsel
- Means “to set the alarm” (choose the time, etc.).
- Slightly different focus: setting the time vs. just activating it.

In everyday speech, people often say:

Aku lupa setel alarm.
Aku lupa nyalain alarm. (colloquial for menyalakan)

So yes, you can use menghidupkan or (meny)etel, but they aren’t always identical in nuance:

nyalakan/menghidupkan alarm: activating it.
setel alarm: configuring/setting the time.

Why is the order “alarm ponsel” and not “ponsel alarm” like in English “phone alarm”?

Indonesian noun order is generally head noun + modifier, the opposite of English.

alarm ponsel
- alarm = head noun
- ponsel = “phone”, describing what kind of alarm
- Literally: “phone alarm”

Compare:

rumah sakit = “house sick” → hospital
tiket pesawat = “ticket plane” → plane ticket
kamera ponsel = phone camera

So “alarm ponsel” is the natural order; “ponsel alarm” would sound wrong.

How do we know this sentence is in the past tense if there’s no past marker like “was” or “did”?

Indonesian usually does not mark tense with verb changes. Instead, context and time expressions tell you whether it’s past, present, or future.

In your sentence, “setelah lembur” (after working overtime) clearly refers to something that already happened, so the whole sentence is understood as past:

Saking lelahnya setelah lembur, saya sampai lupa menyalakan alarm ponsel.
→ I was so tired after working overtime that I forgot to turn on my phone alarm.

If needed, you can add adverbs:

Tadi malam, saking lelahnya setelah lembur, saya sampai lupa…
→ Last night, because I was so tired after overtime, I forgot…

But the verbs themselves (lelah, lupa, menyalakan) do not change form for tense.

How formal is this sentence? Would it sound natural in casual conversation?

This sentence is neutral to slightly formal, mainly because of:

saya (I) → neutral/formal
ponsel (phone) → more neutral/formal than HP

In casual conversation, people might say:

Saking capeknya abis lembur, aku sampe lupa nyalain alarm HP.

Changes:

capek instead of lelah (more colloquial)
abis instead of setelah
aku instead of saya
sampe instead of sampai (spoken reduction)
nyalain instead of menyalakan
HP instead of ponsel

Your original sentence is perfect for writing, storytelling, or polite spoken Indonesian.

Can “setelah lembur” be moved to another position in the sentence?

Yes. Indonesian word order is quite flexible with time expressions. All of these are grammatical, with slightly different emphasis:

Setelah lembur, saking lelahnya, saya sampai lupa menyalakan alarm ponsel.
- Emphasis first on the time (after overtime), then the degree of tiredness.
Saking lelahnya setelah lembur, saya sampai lupa menyalakan alarm ponsel.
- Emphasis on how tired you were (because it was after overtime).
Saking lelahnya, saya sampai lupa menyalakan alarm ponsel setelah lembur.
- Grammatically okay, but could sound like you forgot the alarm after overtime (slightly more ambiguous).

The original one is natural and clear, tying lelahnya directly to setelah lembur.