Saat hujan deras, rumah bibi pernah kemasukan air dari halaman belakang.

Saat means when or at the time when. In this sentence, Saat hujan deras means when it was raining heavily or during heavy rain.

It is a common way to introduce a time clause. Other words that can often work similarly are ketika and waktu.

• Saat hujan deras = when it rains heavily / during heavy rain
• Ketika hujan deras = when it rains heavily
• Waktu hujan deras = when it rains heavily

All three are natural, though saat can sound a little more formal than waktu in some contexts.

In Indonesian, descriptive words usually come after the noun.

So:

• hujan deras = heavy rain
• angin kencang = strong wind
• air panas = hot water

Here, deras describes the intensity of the rain. So hujan deras is the normal word order.

Rumah bibi means aunt’s house.

This is a very common Indonesian possession pattern:

• rumah bibi = aunt’s house
• mobil kakak = older sibling’s car
• buku saya = my book

Indonesian usually does not use an apostrophe like English does. Instead, the possessor simply comes after the noun.

So the structure is:

• rumah = house
• bibi = aunt
• rumah bibi = aunt’s house

Not by itself. Bibi just means aunt.

So rumah bibi literally means the aunt’s house or aunt’s house, and the exact relationship is understood from context. In many real situations, it may indeed mean my aunt’s house, but Indonesian often leaves that kind of information unstated if it is already clear.

If you want to be specific, you could say:

• rumah bibi saya = my aunt’s house

Pernah means something like ever, once, or has/had experienced.

In this sentence, it shows that this happened at least once in the past. So the sentence is not saying that the house always floods during heavy rain, only that it has happened before.

Compare:

• Rumah bibi kemasukan air = Aunt’s house got water in / was entered by water
• Rumah bibi pernah kemasukan air = Aunt’s house once got water in / has been entered by water before

So pernah adds the idea of past experience.

Literally, kemasukan air means something like got entered by water or had water come in.

It comes from:

• masuk = to enter, go in
• ke- -an = an affix pattern that often shows something happening unintentionally, unexpectedly, or affecting the subject

So:

• kemasukan air = to have water get into something

In natural English, this often becomes:

• got water in
• had water come in
• was flooded by water entering
• had water seep in

The important idea is that water came into the house, and it was not intentional.

Because kemasukan focuses on the house as the thing affected by something entering.

Compare these:

• Air masuk ke rumah bibi = Water entered my aunt’s house
• Rumah bibi kemasukan air = My aunt’s house got water in it / was entered by water

Both are possible, but they emphasize different things.

With kemasukan, the house is presented as the affected party. This pattern is very common in Indonesian:

• kemasukan air = got water in
• kemasukan debu = got dust in
• kemasukan pencuri = got a burglar in / was broken into by a burglar

So ke- -an often gives a sense of an unwanted or accidental event affecting the subject.

They are similar, but not exactly the same.

• kemasukan air = water got in
• kebanjiran = got flooded

Kebanjiran usually sounds stronger and more directly means flooding. Kemasukan air can be a bit more specific or a bit milder, depending on context: it emphasizes water entering the house.

So:

• Rumah bibi pernah kemasukan air = Aunt’s house once had water come in
• Rumah bibi pernah kebanjiran = Aunt’s house was flooded once

If a learner translates both simply as flooded, that is often fine, but the nuance is slightly different.

It means from the backyard or from the back yard area.

Breaking it down:

• dari = from
• halaman = yard, courtyard
• belakang = back, rear

So halaman belakang is backyard or rear yard.

In the sentence, this phrase tells you the source or direction the water came from: it entered the house from the back yard.

Indonesian often leaves out words that English requires, especially forms of to be like is, was, and were.

So:

• Saat hujan deras literally looks like when heavy rain
• but naturally means when it was raining heavily or during heavy rain

This is very normal in Indonesian. The language often expresses meaning more compactly, without extra helper verbs.

The sentence has two parts:

1. Saat hujan deras = time clause
2. rumah bibi pernah kemasukan air dari halaman belakang = main clause

So the pattern is:

• Saat + situation, main event

A rough breakdown:

• Saat hujan deras = When it rained heavily
• rumah bibi = aunt’s house
• pernah = once / ever
• kemasukan air = got water in / had water enter
• dari halaman belakang = from the backyard

So the full meaning is something like:

When it rained heavily, my aunt’s house once had water come in from the backyard.

Yes. If you remove pernah, the sentence becomes more neutral and simply states the event.

• Saat hujan deras, rumah bibi kemasukan air dari halaman belakang.

That means:

• When it rained heavily, my aunt’s house got water in from the backyard
• or During heavy rain, my aunt’s house gets water coming in from the backyard, depending on context

Adding pernah specifically tells the listener that this happened at least once as a past experience.

The comma is helpful, but in informal Indonesian it is often omitted.

So both of these are common:

• Saat hujan deras, rumah bibi pernah kemasukan air dari halaman belakang.
• Saat hujan deras rumah bibi pernah kemasukan air dari halaman belakang.

The version with the comma is easier to read because it clearly separates the time clause from the main clause.

Not exactly. Kalau usually means if or when in a more conditional sense.

• Saat hujan deras = when it rained heavily / during heavy rain
• Kalau hujan deras = if it rains heavily / when it rains heavily

So kalau can work in some contexts, but it changes the feel a little. Saat is more purely temporal, while kalau can sound more conditional.

In this sentence, saat is a better match if you are describing a real past situation.

Because of pernah, it usually refers to at least one past event, not a general habit.

So the idea is:

• there was a time when heavy rain happened
• and on at least one such occasion, the aunt’s house had water come in from the backyard

If you wanted to describe a repeated habit, you might use something like:

• Setiap hujan deras, rumah bibi kemasukan air dari halaman belakang.
  = Every time it rains heavily, my aunt’s house gets water in from the backyard

That would sound habitual or repeated.