Harga biskut kecil itu hanya dua puluh sen, jadi anak saudara saya terus membelinya.

In Malay, adjectives usually come after the noun.

• biskut kecil = small biscuit
• rumah besar = big house
• kereta merah = red car

So biskut kecil itu literally follows Malay word order: biscuit small that.

Itu often means that, but in natural English it can also function like the when referring to something specific already known in context.

So:

• biskut kecil itu = that small biscuit / the small biscuit

Malay commonly uses itu after the noun phrase:

• rumah itu = that house / the house
• budak kecil itu = that little child

Yes. Malay often expresses the price of X as:

• harga + noun phrase

So:

• Harga biskut kecil itu = the price of that small biscuit
• literally: price [of] that small biscuit

Malay often leaves out words like of that English requires.

Hanya means only or just.

In this sentence:

• hanya dua puluh sen = only twenty cents

It is placed before the amount it modifies. This is very common:

• hanya RM5 = only 5 ringgit
• hanya seorang = only one person

Dua puluh sen means twenty sen/cents.

Breakdown:

• dua = two
• puluh = tens
• dua puluh = twenty
• sen = cent(s)

Malay nouns usually do not change form for singular/plural, so sen can mean cent or cents depending on context.

Examples:

• sepuluh sen = ten cents
• lima puluh sen = fifty cents
• satu ringgit dua puluh sen = one ringgit and twenty sen

Yes. Jadi here means so, therefore, or as a result.

It links the first clause to the result:

• Harga biskut kecil itu hanya dua puluh sen, jadi...
• The small biscuit cost only twenty cents, so...

In other contexts, jadi can also mean become, so its meaning depends on usage.

Anak saudara can mean nephew or niece. It is a gender-neutral family term unless extra context makes the gender clear.

So:

• anak saudara saya = my nephew / my niece

If needed, speakers can clarify with context or add information such as:

• anak saudara lelaki = nephew
• anak saudara perempuan = niece

Terus here means something like immediately, straightaway, or went ahead and.

So:

• terus membelinya suggests that the person didn’t hesitate and bought it right away

This word often gives a sense of direct continuation after what was just mentioned.

Examples:

• Dia terus pergi. = He immediately left / He went straight away.
• Saya terus makan. = I immediately started eating.

The ending -nya here means it.

So:

• membeli = to buy / buy
• membelinya = to buy it / bought it

In this sentence, -nya refers back to biskut kecil itu.

So:

• anak saudara saya terus membelinya
• = my nephew/niece immediately bought it

This is very common in Malay: pronoun objects can attach to the verb.

Examples:

• melihatnya = see it / saw him/her
• menggunakannya = use it

Membeli is the meN- form of the root beli (buy).

• beli = buy
• membeli = to buy / buy

The meN- prefix is commonly used for active verbs. Its shape changes depending on the first sound of the root word. With beli, it becomes mem-:

• beli → membeli
• baca → membaca
• pakai → memakai

In many everyday contexts, especially casual speech, you may also hear just beli, but membeli is more explicitly standard/formal.

Malay verbs usually do not change form for tense the way English verbs do.

So membeli itself does not mean specifically buy, buys, or bought. The time is understood from:

• context
• time words
• the flow of the sentence

Here, because the sentence describes a completed result (the price was only twenty cents, so my nephew/niece went ahead and bought it), English naturally translates it as bought.

Normally, no. On its own, biskut kecil itu is most naturally understood as that small biscuit or the small biscuit.

If you wanted to clearly show plural, Malay often uses:

• reduplication: biskut-biskut kecil itu = those small biscuits
• or context if plurality is already obvious

Malay is often less explicit than English about singular vs. plural, but in this sentence the singular interpretation is the most natural because of harga and membelinya referring to one item.