Learn Hardcore Malay: Dia tidak mahu beli telefon baru; lagipun gajinya masih rendah. - He/She does not want to buy a new phone; besides, his/her salary is still low.

Dia is a third-person singular pronoun that can mean “he”, “she”, or even “they” (singular, gender-neutral) depending on context. Malay pronouns are not marked for gender.

Without more context, dia just means “that person / he / she” in a gender-neutral way.
If you need to specify gender, you usually add context, e.g.:

Dia (lelaki) itu… – That man / he…
Dia (perempuan) itu… – That woman / she…

Why is tidak used here instead of bukan?

Malay has two main “not” words:

tidak – used to negate verbs and adjectives
bukan – used to negate nouns and equational sentences (X is not Y)

In Dia tidak mahu beli telefon baru, mahu (“want”) is a verb, so you must use tidak.

Compare:

Dia tidak mahu beli telefon baru. – He/She does not want to buy a new phone.
Dia bukan doktor. – He/She is not a doctor.

So here tidak is correct because you are negating the wanting (a verb), not a noun.

What is the difference between tidak and tak?

Tak is simply a colloquial / shortened form of tidak. The meaning is the same: “not / don’t”.

Dia tidak mahu beli telefon baru. – more neutral/standard
Dia tak mahu beli telefon baru. – more casual, everyday speech

Both are widely understood. In spoken, informal Malay, tak is very common; in writing, especially in exams or formal texts, tidak is safer.

Why is there no word for “to” before beli? In English we say “to buy”.

Malay verbs do not need a word like English “to” for infinitives. The base form of the verb can function directly after another verb.

mahu beli – “want to buy”
boleh pergi – “can go”
suka makan – “like to eat”

So Dia tidak mahu beli telefon baru literally strings together mahu (“want”) + beli (“buy”), and that already means “does not want to buy”. No extra particle is needed.

Why is it beli and not membeli?

Beli is the root verb “to buy”.
Membeli is the meN- form of the same verb and is often more formal or used in certain grammatical patterns.

In everyday speech, people very often use the root form after modal-type verbs like mahu, boleh, nak, etc.:

Saya mahu beli buku. – I want to buy a book.
Saya mahu membeli buku. – Also correct; feels slightly more formal / written.

In your sentence, beli is perfectly natural in conversation.
A more formal written version might be:

Dia tidak mahu membeli telefon baharu; tambahan pula, gajinya masih rendah.

Why is baru placed after telefon instead of before, like “new phone”?

In Malay, adjectives usually come after the noun they describe:

telefon baru – literally “phone new” → “new phone”
kereta besar – “car big” → “big car”
rumah mahal – “house expensive” → “expensive house”

So telefon baru is the normal word order.
If you said baru telefon, it would have a different meaning or be ungrammatical in this context.

What exactly does lagipun mean, and how is it used?

Lagipun is a connector meaning roughly:

“besides”
“anyway”
“in addition / moreover”
“after all”

It introduces an additional reason or justification for what was just said.

In your sentence:

Dia tidak mahu beli telefon baru; lagipun gajinya masih rendah.
→ He/She doesn’t want to buy a new phone; besides, his/her salary is still low.

It’s fairly informal / conversational. More formal or neutral alternatives include:

tambahan pula
lagi pula
di samping itu

You can write it as a second clause after a semicolon, or start a new sentence:

Dia tidak mahu beli telefon baru. Lagipun, gajinya masih rendah.

What does the -nya in gajinya mean? Why not just gaji dia?

-nya is a third-person possessive marker or pronoun. When added to a noun, it means “his / her / its / their (singular)” depending on context.

gaji – salary
gajinya – his/her salary

You can often choose between:

gajinya
gaji dia

Both mean “his/her salary”. Differences:

gajinya feels a bit more compact, slightly more formal, and is very common in writing.
gaji dia feels more explicit and colloquial, common in speech.

They are interchangeable in many contexts:

Lagipun gajinya masih rendah.
Lagipun gaji dia masih rendah.

Both are fine and natural.

What does masih add to the sentence? How is it different from lagi?

Masih means “still” in the sense of a situation continuing and not having changed yet.

gajinya masih rendah – his/her salary is still low (it hasn’t improved yet)

Lagi can also mean “still”, but it has several other meanings like “more, again, another”. In many regions:

Dia masih di pejabat. – He is still in the office.
Dia lagi di pejabat. – In some dialects / colloquial speech, also “He’s still in the office.”

In standard / careful Malay, masih is the clearer choice for “still (ongoing state)”. In your sentence, masih is the most natural standard option:

gajinya masih rendah – his/her salary is still low.

How is tense shown here? How do we know if it is present or past?

Malay verbs do not change form for tense (no -ed, -s, etc.). Tense and time are usually understood from context or from time expressions.

Dia tidak mahu beli telefon baru; lagipun gajinya masih rendah.

This could be:

present: He/She does not want to buy a new phone; besides, his/her salary is still low.
past: He/She did not want to buy a new phone; besides, his/her salary was still low.

To be explicit, you add time words:

Semalam dia tidak mahu beli telefon baru… – Yesterday, he/she did not want to buy a new phone…
Sekarang dia tidak mahu beli telefon baru… – Now, he/she does not want to buy a new phone…

Is it correct to say Dia tidak mahu membeli telefon baru; lagipun gajinya masih rendah? Does it change the meaning?

Yes, that sentence is correct. The meaning is essentially the same: “He/She doesn’t want to buy a new phone; besides, his/her salary is still low.”

Differences:

mahu beli – neutral, common in speech and writing
mahu membeli – a bit more formal / written in feel because of the meN- verb form

So you can safely use either, depending on how formal you want to sound.

Could the sentence be written with kerana (“because”) instead of lagipun?

Yes, you can express the relationship more explicitly as “because”:

Dia tidak mahu beli telefon baru kerana gajinya masih rendah.
→ He/She doesn’t want to buy a new phone because his/her salary is still low.

Differences in nuance:

lagipun – adds an extra supporting reason; it sounds like “also / besides, another reason is…”.
kerana – directly marks the cause (“because”).

So:

lagipun: not strictly causal; it adds justification, like “and on top of that…”.
kerana: directly causal, “A does not happen because B”.

Is Dia tidak mahu beli telefon baru; lagipun gajinya masih rendah formal or informal? How would a more formal version look?

The sentence as given is neutral to slightly informal, especially because of:

beli (root verb; fine but casual)
lagipun (informal-ish connector)

A more formal / written version might be:

Dia tidak mahu membeli telefon baharu; tambahan pula, gajinya masih rendah.

Changes:

membeli instead of beli
baharu instead of baru (both understood; baharu is more formal spelling for “new”)
tambahan pula instead of lagipun (more formal connector)

All versions are grammatically correct; you just choose based on context (conversation vs essay, etc.).