Dia belajar tentang sejarah zaman itu.

Because Malay third-person pronouns usually do not mark gender.

• dia can mean he or she
• you understand which one from context
• in formal writing, you may also see ia, but dia is very common in everyday language

So unlike English, Malay does not force you to choose between he and she here.

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

So belajar can mean things like:

• studies
• is studying
• studied
• was studying

The time is normally understood from context, or from time words and aspect markers such as:

• sudah = already
• sedang = in the process of
• akan = will / going to

So this sentence by itself does not specify tense very strongly.

Belajar means to learn or to study.

In this sentence, it means the person is engaging in learning/studying about a topic. A useful contrast is:

• belajar = learn, study
• mengajar = teach
• mempelajari = study/learn something, often in a more direct or formal way

So Dia belajar tentang sejarah zaman itu means the person is learning/studying about that topic, not teaching it.

Tentang means about and introduces the topic of study.

So:

• belajar tentang sejarah = study/learn about history

It helps show that history of that era is the subject matter.

Without tentang, the sentence structure would feel different. For example:

• Dia belajar sejarah usually means He/She studies history as a subject
• Dia belajar tentang sejarah zaman itu means He/She is learning about the history of that era

So tentang makes the topic relationship very clear.

They are different kinds of nouns:

• sejarah = history
• zaman = era, age, period, time

In this sentence, sejarah is the main topic, and zaman itu narrows it down. So the idea is the history of that era/period.

Malay often links nouns directly without a separate word like English of.

So:

• sejarah zaman itu literally looks like history that era
• but the natural meaning is the history of that era

This is very common in Malay. English needs of much more often than Malay does.

Because Malay demonstratives usually come after the noun.

So:

• zaman itu = that era
• buku itu = that book
• rumah itu = that house

This is a basic word-order difference from English. Malay usually says noun + itu/ini, not that/this + noun.

Most directly, itu follows zaman, so it clearly gives you zaman itu = that era.

Then the full phrase becomes:

• sejarah zaman itu = the history of that era

So the most natural reading is that itu identifies zaman, and the whole noun phrase means the history connected with that era.

Malay does not have articles that work like English the and a/an.

That means nouns can appear without an article, and definiteness is understood from:

• context
• word order
• demonstratives like ini and itu

Here, itu helps make the phrase more specific, somewhat like that in English.

Yes, that is possible, and it would sound a bit more direct or formal.

For example:

• Dia mempelajari sejarah zaman itu.

That means roughly He/She studies the history of that era.

The difference is:

• belajar tentang = learn/study about
• mempelajari = study/learn something directly

Both can be correct, but belajar tentang emphasizes the topic as something the person is learning about.

Sometimes yes, especially in casual conversation, if the subject is already obvious from context.

For example, if everyone already knows who you are talking about, Malay may omit the subject. But as a full standalone sentence, keeping dia is normal and clear.

So:

• Dia belajar tentang sejarah zaman itu. = complete and neutral
• omitting dia is more context-dependent

It can suggest either, depending on context, because belajar covers both learn and study.

A useful distinction is:

• belajar sejarah = study history
• belajar tentang sejarah zaman itu = learn/study about the history of that era

So with tentang, the phrase often feels a little more like learning about a topic rather than naming a school subject.