Kalau konfirmasi belum datang malam ini, saya akan memeriksa pemesanan itu lagi besok pagi.

Kalau means if here. It introduces the condition for the main clause.

So the structure is:

Kalau ... , saya akan ...
= If ... , I will ...

A few notes:

• kalau is very common in everyday Indonesian.
• jika can also mean if, but it sounds a bit more formal.
• In casual speech, kalau is often the most natural choice.

Belum means not yet, while tidak usually means not.

That matters because belum suggests that the confirmation may still arrive later.

• konfirmasi belum datang = the confirmation has not arrived yet
• konfirmasi tidak datang = the confirmation did not / does not come

In this sentence, belum is the better choice because the speaker is waiting and still treating the arrival as possible.

Yes. In Indonesian, datang can be used not only for people, but also for things that arrive or come in, such as:

• letters
• packages
• messages
• payments
• confirmation emails

So konfirmasi belum datang is natural and means the confirmation has not arrived yet.

Depending on context, Indonesians might also say:

• konfirmasinya belum masuk
• email konfirmasinya belum datang

But datang is perfectly understandable and natural.

Not really. Konfirmasi itself is the subject.

Indonesian often does not need articles like the or a, so konfirmasi can already mean something like the confirmation if the context is clear.

You could also say:

Kalau konfirmasinya belum datang ...

That version sounds a bit more specific, because -nya often helps mark something already known in the conversation.

So both are possible:

• konfirmasi belum datang = confirmation hasn’t arrived yet
• konfirmasinya belum datang = the confirmation hasn’t arrived yet

Both relate to tonight, but they are not exactly the same.

• malam ini = tonight / this evening
• nanti malam = later tonight

In this sentence, malam ini sounds like the time frame or deadline: if the confirmation has not arrived by tonight, then the speaker will check again tomorrow morning.

If you used nanti malam, the focus would be a bit more on later tonight from now.

So:

• malam ini = more neutral time reference
• nanti malam = more explicitly “later tonight”

Yes, akan could be omitted.

Akan marks future meaning, like will in English:

• saya akan memeriksa = I will check

But Indonesian often leaves out future markers if the time is already clear. Since the sentence already says besok pagi, the future is obvious.

So both are possible:

• saya akan memeriksa pemesanan itu lagi besok pagi
• saya memeriksa pemesanan itu lagi besok pagi

The version with akan sounds a little more explicit and deliberate.

Both can mean to check, but the tone is a little different.

• memeriksa = more formal, careful, or systematic; also can mean inspect/examine
• mengecek = very common everyday word for check
• cek = even more casual

So:

• memeriksa pemesanan sounds a bit more formal or professional
• mengecek pemesanan sounds a bit more conversational

In many situations, either one would work.

This is a very common learner question because both words are related to pesan.

• pesan = to order / book
• pesanan = an order; something that was ordered
• pemesanan = the act or process of ordering/booking; a booking/reservation

In practice:

• pesanan is very common for things like food orders
• pemesanan is often used for bookings, reservations, or the ordering process more generally

So in this sentence, pemesanan fits well if the speaker is talking about a reservation or booking record.

Pemesanan is built from the root pesan.

The pattern peN- ... -an often creates a noun related to:

• the process of doing something
• the result of that action
• a related concept

So:

• pesan = order / book
• pemesanan = ordering, booking, reservation

You do not always need to analyze every affix while speaking, but recognizing this pattern is very helpful for reading and vocabulary building.

Because Indonesian demonstratives usually come after the noun.

So:

• pemesanan itu = that booking
• rumah itu = that house
• buku ini = this book

This is one of the most important word-order differences from English.

Also, itu can sometimes feel like that or even something close to the, depending on context. Here it refers to a specific booking already known to the speaker.

Here lagi means again.

So:

memeriksa pemesanan itu lagi
= check that booking again

This is a very common meaning of lagi.

Be careful, though: lagi can also mean currently / in the middle of in other contexts, for example:

• Saya lagi makan = I’m eating right now

But in this sentence, it clearly means again.

Yes, the placement can vary a bit.

These are all possible:

• memeriksa pemesanan itu lagi
• memeriksa lagi pemesanan itu

Both are natural. The difference is mostly one of rhythm and focus, not basic meaning.

The version in your sentence is very normal and clear.

It can move.

Indonesian word order is fairly flexible with time expressions. For example:

• Kalau konfirmasi belum datang malam ini, saya akan memeriksa pemesanan itu lagi besok pagi.
• Besok pagi, kalau konfirmasi belum datang malam ini, saya akan memeriksa pemesanan itu lagi.
• Kalau konfirmasi belum datang malam ini, besok pagi saya akan memeriksa pemesanan itu lagi.

These all work, but the focus changes slightly.

The original version sounds natural and balanced.

The comma separates the conditional clause from the main clause:

• Kalau konfirmasi belum datang malam ini = the condition
• saya akan memeriksa pemesanan itu lagi besok pagi = the result

In English, we often do the same thing when the if clause comes first.

In Indonesian writing, this comma is normal and helpful. In speech, of course, it would just be a pause.

Memeriksa comes from periksa.

The prefix meN- often forms an active verb. So:

• periksa = check, examine
• memeriksa = to check, to examine

This is a very common verb-forming pattern in Indonesian.

A useful thing to notice is that when meN- is added to a root beginning with p, the p often disappears:

• periksa → memeriksa
• pakai → memakai

Recognizing these sound changes makes Indonesian word formation much easier to understand.