Saya lagi menyapu lantai di dapur, biar rumah tetap rapi.

I am sweeping the kitchen floor, so that the house stays tidy.

Breakdown of Saya lagi menyapu lantai di dapur, biar rumah tetap rapi.

• rumah: the house
• saya: I
• di: in
• dapur: the kitchen
• tetap: still
• lantai: the floor
• rapi: tidy
• menyapu: to sweep
• lagi: more/another
• biar: so that

Questions & Answers about Saya lagi menyapu lantai di dapur, biar rumah tetap rapi.

What does lagi do here? Is it the same as sedang?

Lagi marks an action as in progress (roughly currently / right now). It’s very common in casual speech.
Sedang has the same core meaning but sounds a bit more neutral/formal.

• Saya lagi menyapu... (casual)
• Saya sedang menyapu... (more formal/neutral)
  Both are correct.

Why is it menyapu and not just sapu?

Menyapu is the verb with the meN- prefix, which is the standard active-voice form in Indonesian. The base is sapu (broom/sweep).
In casual spoken Indonesian, people often drop the prefix:

• Standard: Saya lagi menyapu lantai.
• Casual: Saya lagi sapu lantai.
  The version with menyapu is safer for writing and polite speech.

How does the prefix change sapu into menyapu?

This is a common sound change with meN-: when the root starts with s, it often becomes ny.
So: meN- + sapu → menyapu.
You’ll see similar patterns with other roots.

Is menyapu lantai a fixed phrase? Could I say it differently?

Menyapu lantai is the most common collocation for sweep the floor. You can also say:

• Saya lagi menyapu di dapur. (implies sweeping in the kitchen; the object lantai is understood)
  But menyapu lantai is the clearest and most explicit.

Why is di dapur placed after lantai?

Indonesian often follows: Verb + Object + Place.
So menyapu lantai di dapur = sweeping the floor in the kitchen.
You can move the place phrase earlier for emphasis or style:

• Saya lagi menyapu di dapur, biar rumah tetap rapi.
  Both are natural.

What’s the difference between di dapur and ke dapur?

di dapur means in the kitchen (location where the action happens).
ke dapur means to the kitchen (movement/direction).
So:

• Saya menyapu lantai di dapur. = I’m sweeping the floor in the kitchen.
• Saya ke dapur = I’m going to the kitchen.

What does biar mean here, and is it informal?

Here biar means so that / in order that (purpose). It’s common and slightly informal.
More formal/neutral alternatives: supaya or agar.

• ..., biar rumah tetap rapi. (casual)
• ..., supaya/agar rumah tetap rapi. (more formal)

Does biar ever mean something else?

Yes. Besides so that, biar can also mean let / just let depending on context:

• Biar saja. = Just let it be / Leave it.
  In your sentence, the purpose meaning (so that) is the intended one.

What does tetap contribute? How is it different from just rapi?

Tetap means still / remain / keep being.
So rumah tetap rapi implies the house stays tidy (continues to be tidy), not just “is tidy” at one moment.

• rumah rapi = the house is tidy
• rumah tetap rapi = the house stays/remains tidy

Is rapi only for houses? What nuance does it have?

Rapi means neat / tidy / well-arranged. It’s used for spaces, appearance, objects, work, etc.:

• kamarnya rapi = the room is tidy
• bajunya rapi = the clothes look neat
• tulisannya rapi = the handwriting is neat

Why does Indonesian include rumah here instead of just “so it stays tidy”?

Indonesian often states the subject explicitly: biar rumah tetap rapi = so that the house stays tidy.
You could omit rumah only if it’s very obvious from context, but it’s natural to keep it.

Is the comma required? How is this sentence typically spoken?

The comma is helpful in writing to separate the main clause from the purpose clause, but it’s not strictly required.
In speech, you’d usually pause slightly before biar:
Saya lagi menyapu lantai di dapur | biar rumah tetap rapi.

Could I drop Saya? Does it sound more natural?

Yes, Indonesian often drops the subject when it’s clear from context, especially in casual conversation:

• Lagi menyapu lantai di dapur, biar rumah tetap rapi.
  This sounds conversational. Including Saya is also perfectly fine, especially if you’re being clear or starting a new topic.