Learn Hardcore Malay: Di pameran buku itu, saya membeli kamus kecil dan sebuah novel sejarah. - At that book exhibition, I bought a small dictionary and a history novel.

di = at/in (no movement)
- Di rumah = at home
ke = to/towards (movement)
- Ke rumah = to (go to) the house
dalam = inside (the interior of something)
- Dalam rumah = inside the house

So di pameran buku itu is “at that book exhibition”, not “to that book exhibition” or “inside that book exhibition”.

What exactly does pameran buku mean? Is it a fixed phrase?

Pameran = exhibition / show / display
Buku = book

Together, pameran buku literally means book exhibition, which is naturally translated as book fair or book show in English.

This is a common noun + noun combination in Malay, where the second noun specifies the type of the first:

pameran kereta = car exhibition
pameran seni = art exhibition

So yes, pameran buku is a normal, natural phrase for “book exhibition/fair”, not something like “exhibition of a book (one book)”.

Why is itu placed after pameran buku, and what nuance does it add?

Itu is a demonstrative meaning that (as opposed to ini = this).

pameran buku itu = that book exhibition / that book fair (a specific one already known in the context)
pameran buku (without itu) = a book exhibition / book exhibitions in general, not a specific one you both know about

In Malay, the demonstrative normally comes after the noun phrase:

buku itu = that book
kereta merah itu = that red car
pameran buku itu = that book exhibition

So itu here points to a particular fair, maybe something both speakers already know or that has been mentioned earlier.

Why is there a comma after pameran buku itu?

The comma separates an initial location phrase from the main clause:

Di pameran buku itu, = At that book exhibition,
saya membeli… = I bought…

Malay often places a short pause (and comma in writing) after:

initial time phrases:
- Pada hari Isnin, saya pergi ke KL.
initial place phrases:
- Di sekolah, kami belajar Bahasa Melayu.

So the comma is there for clarity and natural rhythm. You could also write it without a comma in very informal writing, but the comma is standard and recommended.

Is the word order Di pameran buku itu, saya membeli... the only correct one? Could I also say Saya membeli ... di pameran buku itu?

Both word orders are correct:

Di pameran buku itu, saya membeli kamus kecil dan sebuah novel sejarah.
- Emphasis is slightly more on the location: At that book exhibition, I bought…
Saya membeli kamus kecil dan sebuah novel sejarah di pameran buku itu.
- More neutral: I bought a small dictionary and a historical novel at that book exhibition.

Malay basic order is Subject–Verb–Object (SVO), but time/place phrases can be moved to the front for emphasis or style, just like English:

Yesterday, I bought a book. / I bought a book yesterday.
Di sana, dia bekerja. / Dia bekerja di sana.

So changing the position is about focus, not grammatical correctness.

How does the verb membeli work? Where does the me- prefix come from, and how is tense shown?

Membeli comes from the root beli = to buy.

meN- + beli → membeli

The meN- prefix (often written me- in dictionaries) turns many roots into active verbs:

meN- + baca (read) → membaca = to read
meN- + tulis (write) → menulis = to write
meN- + beli (buy) → membeli = to buy

Malay normally does not mark tense on the verb itself. Membeli can mean:

I buy
I am buying
I bought

The tense is understood from context or time words:

Semalam saya membeli… = Yesterday I bought…
Sekarang saya membeli… = Now I am buying…

In your sentence, context (a visit to a specific fair) makes “I bought” the natural translation.

Why is there no word for “a” before kamus kecil? How do you say “a small dictionary” in Malay?

Malay does not have a mandatory article like a/an or the. A bare noun can often be translated as “a” or “the”, depending on context.

saya membeli kamus kecil
- can be understood as I bought a small dictionary
- or I bought the small dictionary, if the specific dictionary is known

To make “one (single) small dictionary” very clear, you can use a classifier:

Saya membeli sebuah kamus kecil. = I bought a / one small dictionary.

So kamus kecil alone is fine and natural, and is often translated as “a small dictionary”.

Why do we use sebuah before novel sejarah but not before kamus kecil?

Sebuah is a classifier (measure word) that roughly corresponds to “a / one (for objects)”.

se- = one
buah = a general classifier for countable things

So:

sebuah novel sejarah = a / one historical novel

In your sentence:

kamus kecil (no classifier shown)
sebuah novel sejarah (with classifier)

Possible reasons:

Style / focus: The speaker may want to emphasize that it was one novel, but the exact number of dictionaries is less important (and assumed to be one from context).
Optionality: In everyday speech, classifiers (like buah) are often optional when the meaning is clear.

You could also say:

Saya membeli sebuah kamus kecil dan sebuah novel sejarah.
- I bought a small dictionary and a historical novel.

Both versions are grammatically correct; the original just chooses to make the “one novel” explicit.

Why do the describing words come after the noun, like kamus kecil and novel sejarah, instead of before like in English?

In Malay, most modifiers (adjectives and many describing nouns) come after the main noun:

kamus kecil = small dictionary
- kamus (dictionary) + kecil (small)
buku baru = new book
kereta merah = red car

For novel sejarah:

novel = novel
sejarah = history
Together, novel sejarah is a historical novel (a novel related to history).

So the usual pattern is:

[noun] + [adjective / describing noun]

Not:

kecil kamus
sejarah novel

Those would be incorrect in standard Malay.

Could kamus kecil dan sebuah novel sejarah be plural? How would you say “small dictionaries and a historical novel” or “small dictionaries and historical novels”?

Malay nouns usually do not show plural with a special ending, so:

kamus kecil could mean a small dictionary or small dictionaries (depending on context).

To make plurality clearer, you can:

Use plural markers like beberapa (some), banyak (many), etc.
- beberapa kamus kecil = some small dictionaries
- banyak kamus kecil = many small dictionaries
Use reduplication (noun-noun) to stress plurality (more written/formal or stylistic):
- kamus-kamus kecil = small dictionaries
- novel-novel sejarah = historical novels

Examples:

Saya membeli beberapa kamus kecil dan sebuah novel sejarah.
= I bought some small dictionaries and a historical novel.
Saya membeli beberapa kamus kecil dan beberapa novel sejarah.
= I bought some small dictionaries and some historical novels.

In your original sentence, the most natural reading is one small dictionary and one historical novel, because “at the book fair” sounds like a one-time purchase of two items.

What does dan do here, and do I need a comma before it in Malay?

Dan means and. It simply connects two items in a list:

kamus kecil dan sebuah novel sejarah
= a small dictionary and a historical novel

No comma is needed before dan in a two-item list, and usually you don’t put one even in longer lists:

Saya membeli buku, majalah dan akhbar.
= I bought books, magazines and newspapers.

This is similar to English without the Oxford comma.

Could I say pesta buku instead of pameran buku? Is there any difference?

Both are used, but there is a nuance:

pameran buku
- literally: book exhibition
- tends to sound a bit more formal or exhibition-focused
pesta buku
- literally: book festival / book fair
- sounds more like a big event / fair / festival, often with many activities, promotions, talks, etc.

In many real-life cases (e.g., big commercial events), people often say:

Pesta Buku Antarabangsa Kuala Lumpur (Kuala Lumpur International Book Fair)

In your sentence, Di pameran buku itu... is perfectly correct and natural. You could also say:

Di pesta buku itu, saya membeli…

If the context is more like a fair/festival, pesta buku might even be the more idiomatic choice, but both are understandable and fine.