Learn Hardcore Indonesian: Mestinya dia datang lebih awal, tetapi justru terlambat karena hujan. - He should have come earlier, but instead he was late because of the rain.

Mestinya (from mesti) expresses expectation or obligation softened by context: it means something like “should (by right)” or “was supposed to.” It often implies the plan or norm wasn’t met. It’s close to seharusnya and harusnya, but can feel a bit more colloquial/natural in everyday speech. Compared:

harus = must (strong obligation).
harusnya / seharusnya = should/ought to (normative expectation).
mestinya = should/supposed to (by expectation/plan), very common.
semestinya = should/ought to (more formal/literary).
sebaiknya = it would be better (advice, not obligation).

Does this sentence imply a past meaning like “should have (come earlier)” even though Indonesian has no tense?

Yes. Indonesian is tenseless, so pastness is inferred from context. The contrast with being late and the rain makes the expectation clearly about a past event. You can add time markers for clarity:

Mestinya tadi dia datang lebih awal… (tadi = earlier today)
Mestinya dia sudah datang… (sudah adds the sense of “already by now”)

Why are both tetapi and justru used—aren’t they redundant?

They do different jobs:

tetapi links two contrasting clauses (like “but”).
justru adds the nuance of “on the contrary/ironically/instead,” highlighting the unexpected reversal. You could drop justru and keep tetapi for a plain contrast, or drop tetapi and keep justru if the contrast is obvious:
Mestinya dia datang lebih awal, tetapi terlambat…
Mestinya dia datang lebih awal; justru terlambat…

Can justru go in other positions?

Yes, placement changes focus:

Justru dia terlambat = it was he (of all people) who was late.
Dia justru terlambat = he was the one who ended up late (focus on the outcome).
Dia terlambat justru karena hujan = the rain is precisely the cause. All are grammatical; choose based on what you want to emphasize.

What’s the difference between justru, malah, and bahkan?

justru: contrary to expectation; stronger, more contrastive. Works in formal and informal contexts.
malah (and malahan): similar to “instead/actually,” more casual; often used for unexpected outcomes (sometimes with a negative undertone).
bahkan: “even,” adds intensity, not necessarily contrary. Examples:
Dia justru membantu. (Contrary to what you’d think, he helped.)
Dia malah pergi. (He went instead/actually left, unexpectedly.)
Dia bahkan pergi. (He even left.)

Why is the subject omitted in the second clause (… tetapi justru terlambat …)?

Indonesian allows subject omission when it’s clear from context (a kind of pro-drop). The second clause’s subject is still dia by ellipsis. You can include it for clarity or emphasis:

… tetapi dia justru terlambat …

Can I use tapi, tetapi, namun, or akan tetapi interchangeably?

They overlap but differ in register and grammar:

tapi: informal/spoken.
tetapi: neutral/standard conjunction for writing and speech.
namun: “however,” more formal; often starts a new sentence or follows a semicolon.
akan tetapi: very formal; often used in official writing. All can signal contrast, but in a single sentence link, tetapi is the safest neutral choice.

What’s the nuance difference among dia, ia, and beliau?

dia: general 3rd-person singular; neutral/informal; can be subject or object.
ia: more formal/literary; typically subject-only and not used after prepositions.
beliau: honorific for respected persons (teachers, officials, elders). You could say Ia justru terlambat, but in everyday speech dia is most common.

Is karena hujan the only way to say “because of the rain”? What about gara-gara, akibat, or sebab?

Alternatives and nuance:

karena hujan: neutral, very common.
gara-gara hujan: colloquial, can imply annoyance/blame.
akibat hujan: formal, “as a result of the rain.”
sebab as a connector usually joins two full clauses (Dia terlambat, sebab hujan turun.). As a bare phrase (sebab hujan) is less typical in this slot. Choose based on tone and formality.

Can I move the cause to the front of the sentence?

Yes:

Karena hujan, dia justru terlambat. Fronted adverbials like this normally take a comma.

Why lebih awal and not lebih cepat or lebih dulu?

lebih awal: earlier in time/schedule (best match for arrival time).
lebih cepat: faster speed or finishing earlier; can work for arrival time in casual speech but is less precise.
lebih dulu / lebih dahulu: earlier/before others; common in sequencing actions. Examples:
Dia datang lebih awal.
Proyek selesai lebih cepat.
Kamu berangkat lebih dulu, ya.

Can I say datang awal instead of datang lebih awal?

Not for the same meaning. Datang awal can be understood as “come early” (absolute), but it’s less idiomatic in Indonesian and risks sounding Malay-influenced. For “earlier (than expected/than usual),” use datang lebih awal. For simply “early,” many speakers prefer datang lebih pagi (if morning is implied) or just datang lebih awal.

What’s the role of the prefix in terlambat? Is telat okay?

terlambat: “late,” with ter- marking a resultant state (not on time).
telat: colloquial form of terlambat, very common in speech. Related words:
lambat = slow.
keterlambatan = lateness/delay (noun).
melambat = to become slow(er).
memperlambat = to slow (something) down.

Is the comma before tetapi required?

Recommended when joining two clauses, especially if each has (or implies) its own subject. If the contrast is light or the second clause is short and elliptical, some writers omit it, but the comma is good standard practice:

…, tetapi …

Any pronunciation tips for tricky words like justru and hujan?

j as in English “judge” (dʒ): justru, hujan.
u like “oo” in “food.”
r is a tapped/flapped r.
e in tetapi is the schwa sound (tə).
Final -ng in datang is the velar nasal (ng), not a hard g.

Could I rephrase using bukannya … justru …?

Yes, it’s a common contrary-expectation pattern:

Bukannya datang lebih awal, dia justru terlambat karena hujan. This explicitly contrasts the expected action with the actual outcome.

How is sebaiknya different from mestinya here?

sebaiknya gives advice/recommendation (“it would be better to…”), often for future or general guidance: Sebaiknya dia datang lebih awal.
mestinya judges an expectation that wasn’t met (often about a specific, now-past plan): Mestinya dia datang lebih awal… You can combine sebaiknya with past-time markers for hindsight advice (Tadi sebaiknya kamu datang lebih awal), but it still sounds advisory rather than “supposed to.”

Can I change the position of mestinya?

Yes:

Mestinya dia datang lebih awal… (fronted stance/evaluation)
Dia mestinya datang lebih awal… (slightly tighter focus on the subject) Both are natural; fronting mestinya sounds a bit more evaluative.

What’s the effect of adding sudah: Dia mestinya sudah datang?

sudah adds a completed/“by now” sense. Dia mestinya sudah datang suggests that by this point (reference time), he should already have arrived. Mestinya dia datang lebih awal focuses on comparative earliness versus the schedule or expectation.

Can justru be used with negation?

Yes, to highlight an unexpected negative outcome:

Mestinya dia datang, tetapi dia justru tidak datang.

If I wanted to say “although it rained,” would I use karena?

No. karena means “because.” For “although/even though,” use:

Walaupun hujan, dia …
Meskipun hujan, dia … Those introduce concession, not cause. Here we need cause, so karena hujan (or gara-gara hujan, etc.) is correct.