Ide itu hebat.

It has a very common Indonesian pattern:

• ide itu = that idea / the idea
• hebat = great / impressive

So the sentence is subject + predicate adjective.

A very literal breakdown is idea that great, but the natural English meaning is That idea is great.

In Indonesian, you often do not need a word like is/am/are when a noun is followed by an adjective or another noun phrase.

So:

• Ide itu hebat = That idea is great

This is normal Indonesian.
English needs is, but Indonesian usually does not here.

A useful warning: learners sometimes try to insert adalah, but Ide itu adalah hebat is not natural standard Indonesian.

Here, itu points to a specific idea. It most often means:

• that
• and sometimes, depending on context, something closer to the

So ide itu can be understood as:

• that idea
• or the idea you and the listener already know about

It does not mean English it in this sentence.

Because Indonesian demonstratives usually come after the noun they describe.

So you get:

• ide itu = that idea
• buku itu = that book
• rumah itu = that house

This is different from English, where that usually comes before the noun.

The same thing happens with ini:

• ide ini = this idea

Hebat is an adjective.

In this sentence, it means something like:

• great
• impressive
• excellent
• amazing

For an idea, hebat suggests strong praise. It sounds more powerful than just okay or good.

Also, in other contexts, hebat can sometimes mean powerful, intense, or even severe, so its exact meaning depends on what it describes.

Yes.

• ide hebat = a great idea
• ide itu hebat = that idea is great

The difference is grammatical:

• In ide hebat, hebat directly modifies the noun ide
• In ide itu hebat, hebat is the main predicate of the sentence

So both are correct, but they do different jobs.

Not exactly.

• bagus usually means good, nice, or well-made
• hebat usually means great, impressive, or remarkable

So:

• Ide itu bagus = That idea is good
• Ide itu hebat = That idea is great / impressive

For praising an idea strongly, hebat sounds stronger than bagus.

Because ide is the standard Indonesian form of that word.

Indonesian has borrowed many words from other languages, but their spelling is often adapted to Indonesian patterns. So English idea becomes Indonesian ide.

A more native-sounding alternative in some contexts is gagasan, but ide is very common and natural.

You would say:

• Ide ini hebat

Just change itu to ini:

• itu = that
• ini = this

And just like itu, ini usually comes after the noun.

To make it negative, use tidak before the adjective:

• Ide itu tidak hebat = That idea is not great

To make it a question, you can use intonation in speech:

• Ide itu hebat? = Is that idea great?

Or a more explicit/formal question:

• Apakah ide itu hebat? = Is that idea great?