Kenaikan pangkat itu belum tentu.

In Malay, demonstratives like ini and itu normally come after the noun, not before it.

So:

• rumah itu = that house
• orang ini = this person
• kenaikan pangkat itu = that promotion

So Malay structure is closer to promotion that, even though the natural English translation is that promotion. In context, itu can also make the noun phrase feel more definite, like the promotion.

It is a noun phrase built from two parts:

• kenaikan = increase / rise
• pangkat = rank, grade, or position

More specifically, kenaikan comes from the root naik (to go up / rise) with the circumfix ke-...-an, which often forms nouns.

So:

• naik = go up
• kenaikan = a rise / an increase

Together, kenaikan pangkat literally means a rise in rank, which is the standard way to say a promotion.

Yes. Kenaikan pangkat is a very normal and standard way to say promotion in a work or career context.

Malay also has promosi, but that often refers to promotion in the advertising or marketing sense. So if you mean someone moving up in rank or position, kenaikan pangkat is usually the clearer choice.

Malay often does not use a separate word for is / am / are in simple sentences like this.

So:

• Kenaikan pangkat itu belum tentu

literally looks like:

• That promotion not-yet certain

But the natural English meaning is:

• That promotion is not certain yet

This is standard Malay grammar. Nothing is missing.

Belum means not yet, and tentu means certain, definite, or sure.

Together, belum tentu is a very common expression meaning:

• not certain yet
• not definite yet
• not guaranteed
• sometimes not necessarily, depending on context

In this sentence, the most natural meaning is not certain yet.

They are not the same.

• belum tentu = not certain yet / not necessarily
• tidak tentu = uncertain, irregular, not fixed, or unpredictable

In Kenaikan pangkat itu belum tentu, the idea is that the promotion has not been decided or confirmed yet.

If you said tidak tentu, it would sound less natural here and might suggest something more like unstable or not fixed, rather than simply still undecided.

Yes. Kenaikan pangkat itu belum pasti is also very natural.

Both tentu and pasti can mean certain / sure / definite.

A small nuance:

• belum tentu can sometimes also mean not necessarily
• belum pasti often feels a bit more like not yet confirmed

In this sentence, both are good.

Not always. Even though belum literally has a not yet sense, belum tentu often works as a fixed expression.

For example:

• Mahal belum tentu bagus. = Expensive does not necessarily mean good.

That is not really about time. It means one thing does not automatically lead to the other.

But in Kenaikan pangkat itu belum tentu, the not yet decided idea fits very naturally.

Normally, no. The natural order is:

• Kenaikan pangkat itu = the noun phrase
• belum tentu = the predicate

So:

• Kenaikan pangkat itu belum tentu is the standard form.

You could add a pause for emphasis:

• Kenaikan pangkat itu, belum tentu.

But itu normally stays after the noun it modifies.

It is neutral standard Malay. It sounds natural in conversation, workplace discussion, and writing.

If you want to sound slightly more explicit, you could also say:

• Kenaikan pangkat itu belum pasti lagi.
• Kenaikan pangkat itu masih belum pasti.

But the original sentence is already perfectly natural and correct.