Saya simpan bukti pembelian.

Both can be correct, but they belong to slightly different styles.

• menyimpan is the fully marked standard verb form.
• simpan without the prefix is very common in everyday speech and in less formal writing.

So:

• Saya menyimpan bukti pembelian. = more formal/fully standard
• Saya simpan bukti pembelian. = very natural in conversation and common usage

A learner should know both. If you want to sound safely formal, use menyimpan.

No, not by itself. Malay verbs usually do not change form for tense.

So Saya simpan bukti pembelian could mean different things depending on context:

• I keep the proof of purchase
• I kept the proof of purchase
• I will keep the proof of purchase

Time is usually understood from context or added with time words such as:

• semalam = yesterday
• sekarang = now
• nanti = later

For example:

• Semalam saya simpan bukti pembelian itu.
• Saya akan simpan bukti pembelian itu.

Bukti means proof or evidence.

Pembelian means purchase or buying.

So bukti pembelian literally means proof of purchase.

In real life, this often refers to things like:

• a receipt
• an invoice
• a payment record
• any document showing that something was bought

So it is slightly broader than just receipt.

Because pembelian is a noun, while membeli is a verb.

• beli = buy
• membeli = to buy
• pembelian = purchase / the act of buying

After bukti you need a noun phrase, not a verb.
That is why bukti pembelian works, but bukti membeli would not sound right in normal Malay.

Malay does not use articles in the same way English does.

So bukti pembelian can mean:

• a proof of purchase
• the proof of purchase
• just proof of purchase

The exact meaning depends on context.

If you want to make it more specific, Malay can add words like:

• itu = that / the one already known
• ini = this

For example:

• Saya simpan bukti pembelian itu. = I keep that/the proof of purchase.

Yes, this sentence follows the basic Subject–Verb–Object order:

• Saya = subject
• simpan = verb
• bukti pembelian = object

So it works very much like:

• I keep proof of purchase.

That makes this sentence fairly straightforward for an English speaker.

Sometimes, yes, but it changes how the sentence feels.

• Saya simpan bukti pembelian. = I keep the proof of purchase.
• Simpan bukti pembelian. = Keep the proof of purchase. This sounds like an instruction or command.

So if you drop saya, the sentence may stop sounding like a statement and start sounding like an imperative.

It is fairly neutral, but with a slightly conversational feel because of simpan instead of menyimpan.

• Saya is neutral and polite.
• simpan without meN- is common and natural in speech.
• menyimpan would sound more formal or careful.

So the sentence is perfectly normal, especially in everyday Malay.

Yes, but the tone changes.

• Saya = neutral, polite, standard
• Aku = more informal, personal, and only suitable in the right social context

So:

• Saya simpan bukti pembelian. = safe, neutral
• Aku simpan bukti pembelian. = casual, familiar

A learner should usually default to saya unless they are sure aku is appropriate.

Yes, in many situations that is what people mean. But literally it means proof of purchase, which is broader than receipt.

If you want to say receipt more specifically, you might hear:

• resit
• struk in some contexts and regions

So:

• bukti pembelian = proof of purchase in general
• resit = receipt specifically

Yes. That is possible and puts more emphasis on bukti pembelian.

Compare:

• Saya simpan bukti pembelian. = neutral statement
• Bukti pembelian saya simpan. = As for the proof of purchase, I keep it / The proof of purchase, I keep it

This kind of fronting is possible in Malay for emphasis or topic marking.

It comes from the root beli with the circumfix peN- ... -an:

• beli = buy
• pembelian = purchase / buying

This pattern often creates nouns related to actions or processes.

Other examples:

• bayar = pay → pembayaran = payment
• jual = sell → penjualan = sale / selling

So pembelian is the noun form associated with buying.

Not always. A native speaker might choose different versions depending on style and situation, for example:

• Saya simpan bukti pembelian.
• Saya menyimpan bukti pembelian.
• Saya simpan resit itu.
• Tolong simpan bukti pembelian.

All are natural in the right context. The original sentence is simple, clear, and very usable.