Ibu memarahi adik saya karena dia nakal dan melempar bola ke jendela.

Usually, yes: ibu commonly means mother/mom.

But Indonesian ibu can also mean:

• Mrs.
• ma’am
• an adult woman in a respectful way

In this sentence, the most natural reading is Mother scolded my younger sibling...

One small note: the capital I in Ibu does not prove it is a name-like title here, because it is also the first word of the sentence.

Because marah and memarahi do different jobs.

• marah = angry
  • Ibu marah. = Mother is angry.
• memarahi = to scold / be angry at someone
  • Ibu memarahi adik saya. = Mother scolded my younger sibling.

So memarahi is a verb formed from marah. The ending -i often helps make a verb that targets someone or something. Here, memarahi means directing anger toward someone.

In Indonesian, possessors usually come after the noun.

So:

• adik saya = my younger sibling
• rumah saya = my house
• teman saya = my friend

This is the normal pattern:

• noun + possessor

So adik saya is the natural Indonesian word order.

It can mean either one.

adik means:

• younger sibling
• or sometimes younger brother/sister, depending on context

Indonesian often does not mark gender unless it is important.

So adik saya could mean:

• my younger brother
• my younger sister
• my younger sibling

You need context to know which one.

Because dia can mean:

• he
• she

And in this sentence, it could also potentially refer back to more than one person if there were no context.

Most naturally, though, dia refers to adik saya, because the sentence says Mother scolded the younger sibling because that person was naughty and threw a ball at the window.

So the natural interpretation is:

• Ibu memarahi adik saya karena dia nakal...
• Mother scolded my younger sibling because he/she was naughty...

Still, grammatically, dia itself does not tell you gender.

Yes. Indonesian sometimes leaves this kind of ambiguity in place if the meaning is obvious from context, but you can make it clearer.

For example:

• Ibu memarahi adik saya karena adik saya nakal dan melempar bola ke jendela.

This repeats adik saya instead of using dia.

That sounds a bit more explicit, though slightly less smooth because of the repetition. In natural Indonesian, speakers often keep dia if they think the listener will understand.

Not exactly.

nakal usually means:

• naughty
• mischievous
• badly behaved

It often describes a child who is behaving in an annoying or troublesome way, not necessarily someone who is morally evil.

So in this sentence, nakal is much closer to:

• naughty
• mischievous

than to a strong word like:

• evil
• bad person

karena means because.

It introduces the reason:

• Ibu memarahi adik saya = Mother scolded my younger sibling
• karena dia nakal dan melempar bola ke jendela = because he/she was naughty and threw a ball at the window

So the structure is:

• main clause
  • karena
    • reason clause

This is very similar to English because.

Because Indonesian does not usually need a verb like to be in sentences like this.

So:

• dia nakal literally looks like he/she naughty
• but it means he/she is naughty or he/she was naughty, depending on context

Indonesian often leaves tense unstated unless it needs to be made clear. Time is usually understood from context or from time words like:

• kemarin = yesterday
• tadi = earlier
• sekarang = now

So dia nakal can work without any equivalent of is/was.

In natural English, here it is best understood as throw a ball at the window.

Word by word:

• melempar = to throw
• bola = ball
• ke = to / toward
• jendela = window

So literally it is something like:

• throw a ball toward the window

In context, English usually says:

• throw a ball at the window

If you wanted to be more explicit in Indonesian, you might say:

• melempar bola ke arah jendela = throw a ball toward the window / in the direction of the window

But the original sentence is natural.

Indonesian ke covers a range of meanings related to movement toward a place or target.

So ke jendela literally means:

• to the window
• toward the window

When translated naturally into English with throw, we often use:

• at the window

This is a good example where Indonesian and English do not line up word-for-word. The Indonesian expression is normal even though English prefers at in this context.

It gives two linked reasons about the same person:

• dia nakal = he/she was naughty
• (dia) melempar bola ke jendela = (he/she) threw a ball at the window

The second dia is omitted because Indonesian often leaves out repeated subjects when they are understood.

So the meaning is basically:

• because he/she was naughty and threw a ball at the window

Yes, very natural.

Its basic structure is:

• Ibu = subject
• memarahi = verb
• adik saya = object
• karena... = reason clause

So:

• Ibu memarahi adik saya = Mother scolded my younger sibling
• karena dia nakal dan melempar bola ke jendela = because he/she was naughty and threw a ball at the window

This is a very normal and straightforward Indonesian sentence pattern.