Dia bukan sahaja pandai dalam jurusan sejarah, malah dia juga rajin membantu kelab universiti.

It is a paired structure meaning not only ... but also ....

So:

• bukan sahaja = not only
• malah = in fact / moreover / but also
• juga = also

In this sentence, the speaker is adding a second positive quality after the first one:

• first quality: good in the history major
• second quality: diligent in helping the university club

A very close English pattern is:

He/She is not only good in history, but also diligent in helping the university club.

Because bukan sahaja is a very common fixed expression in Malay.

Even though learners are often taught that:

• tidak usually negates verbs and adjectives
• bukan usually negates nouns or identities

the phrase bukan sahaja ... malah/tetapi juga ... is idiomatic and standard.

So here, you should learn bukan sahaja as a set phrase meaning not only.

Dia can mean either he or she. Malay third-person singular pronouns usually do not show gender.

So without more context, this sentence could refer to:

• a male student
• a female student

You have to get that information from context, not from dia itself.

Here, pandai is closer to good at or skilled in, not just generally intelligent.

Malay pandai can mean:

• clever / smart
• good at doing something
• skilled in a subject or activity

In this sentence, because it is followed by dalam jurusan sejarah, the meaning is more like:

• good in the history major
• good at history
• skilled in the field of history

So it is describing ability in a specific academic area.

Jurusan usually means major, specialization, stream, or field of study.

So jurusan sejarah means:

• history major
• specialization in history
• the field of history

In a university context, jurusan sejarah is most naturally understood as the history major.

Here, dalam means in in an abstract sense, not a physical inside.

It marks the area or field where the person is good:

• pandai dalam jurusan sejarah = good in the history major / field

Malay often uses dalam with areas of knowledge, topics, or fields. It helps show the domain in which the quality applies.

A learner might also see similar phrases like:

• mahir dalam matematik = skilled in mathematics
• cemerlang dalam pelajaran = excellent in studies

Yes, it can be left out, but repeating it sounds natural and helps make the sentence balanced.

Current sentence:

Dia bukan sahaja pandai dalam jurusan sejarah, malah dia juga rajin membantu kelab universiti.

With omission:

Dia bukan sahaja pandai dalam jurusan sejarah, malah juga rajin membantu kelab universiti.

Both are understandable, but repeating dia:

• makes the second clause clearer
• creates a nice parallel structure
• is very common in Malay

So the repetition is not strange; it is normal and often stylistically better.

Rajin means more than just hardworking. It often suggests that someone:

• is diligent
• is willing
• does something regularly
• is not lazy about doing it

So rajin membantu does not just mean the person helped once. It suggests a habit or attitude:

• diligent in helping
• always willing to help
• often helps

This makes the description stronger than simply saying membantu.

Because in Malay, it is very common for an adjective like rajin to come before a verb and describe someone’s habitual attitude toward that action.

So:

• rajin membantu = diligent / willing / regular in helping

If you say membantu dengan rajin, it is understandable, but it sounds less natural in many everyday contexts. Malay usually prefers the simpler structure:

• rajin belajar
• rajin bekerja
• rajin membantu

This pattern is very common.

Because membantu is a transitive verb, so it can take a direct object.

Here:

• membantu kelab universiti = help the university club

That means the club is what is being helped.

If you said membantu di kelab universiti, the meaning would shift more toward location:

• helping at the university club

So the original sentence focuses on what is being helped, not where the helping happens.

It is a noun-noun combination:

• kelab = club
• universiti = university

Together, it means something like:

• university club
• the club at the university

Malay often leaves definiteness unstated, so kelab universiti can mean:

• a university club
• the university club

Which one is intended depends on context.

If the speaker wanted to make it more clearly specific, they might add something like:

• kelab universiti itu = that university club / the university club

Yes. Some common alternatives are:

• tetapi juga = but also
• bahkan = even / indeed / in fact
• malahan = a slightly expanded form of malah

For example:

• bukan sahaja ..., tetapi juga ...
• bukan sahaja ..., malah ...
• bukan sahaja ..., bahkan ...

They are similar, but malah often feels a little smoother or slightly more formal/written than very conversational tapi.

Yes, it is natural and grammatically fine.

It sounds like standard Malay, especially in writing or formal speech. A few features that make it sound polished are:

• bukan sahaja ... malah ... juga as a structured connector
• repetition of dia for balance
• rajin membantu as a natural descriptive phrase

In more casual speech, someone might choose simpler wording, but the sentence you gave is perfectly normal and clear.