Learn Hardcore Malay: Laporan itu pasti milik dia, bukan saya punya. - That report is definitely his/hers, not mine.

So “laporan itu” is literally report that, but it means “that report” or “the report” in natural English. This is normal Malay word order for “that X / the X”.

What is the function of “pasti” in this sentence?

Pasti means “definitely / certainly / surely”.

In “Laporan itu pasti milik dia”, pasti is an adverb of certainty modifying the predicate milik dia:

Laporan itu milik dia. = The report belongs to him/her.
Laporan itu pasti milik dia. = The report definitely belongs to him/her.

You usually place pasti before the part it modifies:

Dia pasti datang. = He/She will definitely come.
Mereka pasti tahu. = They definitely know.

What does “milik” mean, and how does “milik dia” work grammatically?

Milik is a noun/relational word meaning “ownership / property / belonging”.

Structure: milik + pronoun/noun = the possession of X / belonging to X

So:

milik dia = his/her property / belonging to him/her
milik saya = my property / belonging to me
milik syarikat = the company’s property

In the sentence:

Laporan itu pasti milik dia
literally: That report is definitely (the) belonging of him/her
natural English: “That report definitely belongs to him/her.”

So milik dia functions like “belongs to him/her” or “his/hers (as owner)”.

Why is “dia” used and not something like “he” vs “she”? Does “dia” show gender?

Dia is a third-person singular pronoun that covers both “he” and “she”.

Malay does not normally mark gender in pronouns:

dia = he / she
milik dia = his / hers
kawan dia = his friend / her friend

The gender is understood from context, not from the word itself.

In more formal or respectful contexts, you might also see:

beliau = respectful “he/she” (for people you respect, like teachers, officials)
- Laporan itu pasti milik beliau.

But gender is still not marked; beliau is also gender-neutral.

Why is “bukan” used in “bukan saya punya”, and not “tidak”?

Malay has two main negators: bukan and tidak.

bukan negates nouns, pronouns, and equational statements (X is Y).
tidak negates verbs and adjectives.

Examples:

Ini bukan buku saya. = This is not my book. (noun)
Dia bukan doktor. = He/She is not a doctor. (noun)
Dia tidak datang. = He/She did not come. (verb)
Dia tidak penat. = He/She is not tired. (adjective)

In “bukan saya punya”:

saya punya is functioning as a noun phrase meaning mine.
So you need bukan, not tidak.

“Tidak saya punya” would be ungrammatical.

What does “saya punya” mean, and how does “punya” work here?

Punya is a word related to possession. In this structure:

saya = I / me
saya punya = literally my possession → functionally “mine”

So “bukan saya punya” means “not mine”.

Some common patterns:

Ini buku saya. = This is my book.
Ini bukan buku saya, ini buku dia. = This isn’t my book, it’s his/hers.
Ini saya punya. = This is mine.
Itu bukan saya punya. = That is not mine.

In your sentence, the noun laporan (report) is understood from context, so people just say:

…, bukan saya punya.
≈ …, it’s not mine.

More formal equivalent: “bukan milik saya” = not my property / not mine.

Why isn’t “laporan” repeated in the second part? Why not say “bukan laporan saya”?

Malay commonly drops repeated nouns when they’re obvious from context.

Full, explicit version:

Laporan itu pasti milik dia, bukan laporan saya.
= That report definitely belongs to him/her, not my report.

Natural, shorter version:

Laporan itu pasti milik dia, bukan saya punya.
= That report definitely belongs to him/her, not mine.

The listener already knows you’re talking about “laporan”, so it’s omitted. English does something similar:

That report is definitely his, not mine.
(You don’t repeat “report” either.)

Is “saya punya” formal or informal? How natural is this whole sentence?

“Saya punya” is colloquial / neutral spoken Malay. It’s very common in everyday speech and informal writing.

The sentence:

Laporan itu pasti milik dia, bukan saya punya.

feels like neutral conversational Malay, not very formal but not slang either.

A more formal version would avoid punya and use milik both times, and maybe beliau:

Laporan itu pasti milik beliau, bukan milik saya.
= That report definitely belongs to him/her, not to me.

So:

Talking to friends/colleagues: current sentence is fine.
Writing a formal report/letter: prefer “bukan milik saya”.

Can I say “laporan itu milik dia, bukan saya punya” without “pasti”? Does that change the meaning much?

Yes, you can drop pasti:

Laporan itu milik dia, bukan saya punya.
= That report belongs to him/her, not mine.

Difference:

With pasti → you are expressing certainty / strong confidence:
- “That report definitely belongs to him/her…”
Without pasti → neutral statement of fact:
- “That report belongs to him/her…”

Grammatically, both are correct; pasti just adds the nuance of certainty.

Could I say “laporan itu pasti dia punya” instead of “milik dia”? What’s the difference?

Yes, you can say:

Laporan itu pasti dia punya.
≈ That report is definitely his/hers.

Difference in feel:

milik dia
- Slightly more formal / standard.
- Focuses on ownership in a more “textbook” way.
- Suitable in written or semi-formal contexts.
dia punya
- More colloquial / conversational.
- Very common in speech.
- Sounds a bit more relaxed.

Meaning-wise, they both say that the report belongs to him/her. In a fully colloquial version, you might have:

Laporan itu pasti dia punya, bukan saya punya.

In a more formal version:

Laporan itu pasti milik dia, bukan milik saya.

What is the overall structure of the sentence? Is it like two clauses contrasted with “not”?

Yes, the sentence is structured as a contrast between two ownership claims:

Laporan itu pasti milik dia,
= That report definitely belongs to him/her,
bukan saya punya.
= (and) not mine.

So the pattern is:

[Statement A], bukan [Statement B].

This is very common in Malay for contrast:

Ini untuk kamu, bukan untuk saya.
= This is for you, not for me.
Dia orang Malaysia, bukan orang Indonesia.
= He/She is Malaysian, not Indonesian.

In your sentence, bukan negates the implied “…laporan itu (adalah) saya punya” → “the report is mine”.