Kami tidak keluar sampai badai reda, lalu kami membuka jendela.

We don’t go out until the storm lets up, then we open the window.

Breakdown of Kami tidak keluar sampai badai reda, lalu kami membuka jendela.

• sebuah: a
• tidak: not
• kami: we
• lalu: then
• sampai: until
• jendela: the window
• membuka: to open
• badai: the storm
• keluar: to go out
• reda: to let up/subside

Questions & Answers about Kami tidak keluar sampai badai reda, lalu kami membuka jendela.

Why does the sentence use kami and not kita?

Kami means we (but not you) (exclusive). Kita means we (including you) (inclusive).
So Kami tidak keluar... implies the listener is not part of the group that stayed inside.

What does tidak negate here, and how is it different from bukan?

Tidak negates verbs and adjectives: tidak keluar = did not go out.
Bukan negates nouns/identity/classification: bukan dokter = not a doctor.
Because keluar is a verb, tidak is correct.

Does keluar mean “leave” or “go outside”? How broad is it?

Keluar literally means to go out / exit. Depending on context it can be:

• leaving a room/house: keluar rumah (go out of the house)
• going outside: keluar (go out)
• coming out (of something): keluar dari... (come out from...)

Here, with the storm context, it naturally reads as go outside.

How does sampai work here? Is it “until” or “to (a place)”?

Sampai has two common uses: 1) until + a time/event: sampai badai reda = until the storm calmed down
2) arrive/reach a place/time: sampai di rumah = arrive at home

In this sentence it’s the until meaning.

Is Kami tidak keluar sampai badai reda ambiguous—could it mean they only went out when the storm calmed down?

In Indonesian, this structure normally means they did not go out before/during the storm; they waited until it calmed down.
If you want to make the “only then did we go out” idea extra explicit, you can say:

• Kami baru keluar setelah badai reda. (We only went out after the storm calmed down.)

What is badai, and can it refer to any kind of storm?

Badai means storm (often a strong storm, windstorm, severe weather). It’s a general word and can be used broadly.
For specific types you might also see:

• badai petir (thunderstorm)
• topan (typhoon/cyclone, more technical/specific)

What does reda mean, and what kinds of things can be reda?

Reda means to subside / die down / calm down. It’s commonly used for:

• weather: badai reda (the storm subsides)
• pain: nyeri reda (pain subsides)
• emotion/tension: amarah reda (anger subsides)

What is the function of lalu in the sentence?

Lalu means then / after that / and then, marking the next event in sequence: ..., lalu kami membuka jendela. = ..., then we opened the window.
It’s similar to kemudian (then/afterwards). Lalu is very common in narrative.

Why is kami repeated in the second clause? Could it be omitted?

Repeating the subject (kami) is common for clarity, especially in writing.
It can be omitted if the subject is clearly the same:

• Kami tidak keluar sampai badai reda, lalu membuka jendela.
  This still sounds natural, but repeating kami is a safe, clear choice.

What does membuka show that buka doesn’t?

Membuka is the active verb with the meN- prefix: to open (something).
Buka can be:

• an informal verb form in casual speech, or
• a base form used in commands/headlines.

In a normal narrative sentence, membuka jendela is the standard form.

Is jendela “a window” or “the window”? How does Indonesian handle articles?

Indonesian doesn’t have a/the. Jendela can mean a window or the window, depending on context.
If you need to specify, you can add:

• sebuah jendela (a window)
• jendela itu (that/the window)
• jendela ini (this window)

What does the comma do here, and is the punctuation required?

The comma separates two linked clauses: 1) Kami tidak keluar sampai badai reda
2) lalu kami membuka jendela

It’s good style in writing, especially with lalu, but in informal writing it might be omitted. In speech, you’d naturally pause there.

Could sampai be replaced with hingga or setelah? What changes?

Yes, with small differences:

• sampai / hingga = until (very similar; hingga can sound a bit more formal)
  → Kami tidak keluar hingga badai reda.
• setelah = after (focuses on the time after the event, not the waiting up to it)
  → Kami tidak keluar setelah badai reda sounds off for the intended meaning (it would suggest “we didn’t go out after it calmed down”).
  For the intended meaning, setelah fits better with baru: Kami baru keluar setelah badai reda.