Mereka terpaksa mengganti perancah yang tidak aman.

Terpaksa means something like forced to, had no choice but to, or reluctantly had to.

So Mereka terpaksa mengganti... suggests that they did not really want to do it, but circumstances made it necessary.

By contrast, harus just means must / have to. It can sound more neutral.

• Mereka harus mengganti perancah... = They have to replace the scaffolding.
• Mereka terpaksa mengganti perancah... = They were forced to replace the scaffolding / They had no choice but to replace it.

So terpaksa adds a sense of pressure, compulsion, or lack of choice.

Ganti is the base word, meaning replace, change, or substitute.

Mengganti is the verb form with the prefix meng-, which is very commonly used to form active transitive verbs in Indonesian.

Here:

• ganti = replace/change (root)
• mengganti = to replace

Because the sentence means they replace something, Indonesian normally uses the active verb form mengganti.

So:

• Mereka mengganti perancah = They replace the scaffolding.

Using just ganti in a full formal sentence would usually sound incomplete or less standard.

The prefix meng- changes form depending on the first sound of the root word.

The root here is ganti. Since it begins with g, the prefix appears as meng-, giving:

• meng- + ganti = mengganti

This is part of a broader pattern in Indonesian verb formation. For example:

• meng- + guna → mengguna- related forms
• mem- + baca → membaca
• men- + tulis → menulis

You do not need to memorize every phonological detail right away, but it is useful to recognize that mengganti is just the active verb built from ganti.

Perancah means scaffold or scaffolding.

It is a correct Indonesian word, but in everyday speech some speakers may use other words too, including terms influenced by technical or industry usage. Still, perancah is a standard dictionary word and is perfectly fine.

Depending on context, it may refer to:

• a single scaffold structure
• scaffolding in general

Like many Indonesian nouns, it does not automatically show singular or plural unless the context makes that clear.

Yang tidak aman describes perancah.

It means that is not safe or unsafe.

So the structure is:

• perancah = scaffolding
• yang tidak aman = that is unsafe

Together:

• perancah yang tidak aman = the unsafe scaffolding / scaffolding that is unsafe

The word yang introduces a descriptive clause attached to the noun before it.

Yes, you could say perancah tidak aman, but the structure is slightly different.

• perancah yang tidak aman = scaffolding that is unsafe
• perancah tidak aman = unsafe scaffolding / the scaffolding is unsafe, depending on context

Using yang makes the description clearly modify the noun in a relative-clause-like way. It is often a very natural way to say the X that is Y.

In this sentence, perancah yang tidak aman sounds very clear and standard.

Tidak is used to negate adjectives and verbs.

Since aman is an adjective meaning safe, the correct negation is:

• tidak aman = not safe / unsafe

Bukan is generally used to negate nouns or noun phrases, not adjectives.

Compare:

• Ini tidak aman. = This is not safe.
• Ini bukan perancah. = This is not scaffolding / This is not a scaffold.

So in your sentence, tidak aman is exactly right.

Yes, often it could.

• tidak aman = not safe / unsafe
• berbahaya = dangerous

They are close in meaning, but not always identical.

Tidak aman focuses on the lack of safety. Berbahaya focuses more directly on danger or hazard.

So:

• perancah yang tidak aman = scaffolding that is not safe
• perancah yang berbahaya = dangerous scaffolding

In many practical contexts, both would work, but tidak aman may sound a little more neutral or technical.

Mereka means they or them. It is plural.

It does not mean he or she. For singular third person, Indonesian usually uses:

• dia
• ia (more formal/written)

A useful point for English speakers is that Indonesian pronouns do not mark gender the way English does. So:

• dia can mean he or she
• mereka means they

In your sentence, mereka clearly refers to more than one person.

Not necessarily. Indonesian verbs do not change form for tense the way English verbs do.

So Mereka terpaksa mengganti perancah yang tidak aman could mean:

• They were forced to replace the unsafe scaffolding.
• They are forced to replace the unsafe scaffolding.
• They had to replace the unsafe scaffolding.

The exact time usually comes from context, or from time words such as:

• kemarin = yesterday
• tadi = earlier
• sekarang = now
• besok = tomorrow
• sudah = already
• akan = will

Without extra context, the sentence itself does not explicitly mark tense.

It is an active sentence.

You can tell because:

• mereka is the doer
• mengganti is an active verb with meng-
• perancah yang tidak aman is the thing being replaced

So the structure is:

• Subject: mereka
• Verb: terpaksa mengganti
• Object: perancah yang tidak aman

A passive version would look different, for example:

• Perancah yang tidak aman terpaksa diganti. = The unsafe scaffolding had to be replaced.

Here, diganti is passive.

Yes. Indonesian nouns usually do not have separate singular and plural forms the way English nouns do.

So perancah could mean:

• scaffold
• scaffolding
• scaffolds

The exact meaning depends on context.

If the speaker wants to make plurality very explicit, Indonesian can use reduplication:

• perancah-perancah

But in many real sentences, this is unnecessary because context already tells you whether one or several structures are meant.

That sense comes mainly from terpaksa.

The word terpaksa often implies:

• external pressure
• necessity due to circumstances
• lack of alternatives

So the sentence does not just say they replaced the scaffolding. It says they did so because they were compelled to.

For example, maybe:

• it failed a safety inspection
• it was unstable
• regulations required replacement

That nuance is built into terpaksa.

This is the normal and natural word order.

The pattern is:

• Mereka = subject
• terpaksa mengganti = verbal phrase
• perancah yang tidak aman = object + description

So the sentence is very standard Indonesian.

You could rearrange parts in special contexts for emphasis, but the original version is the clearest and most neutral.

For example:

• Perancah yang tidak aman itu terpaksa mereka ganti.

This puts more emphasis on the unsafe scaffolding, but it is less neutral than the original sentence.