Learn Hardcore Malay: Dia bercakap dengan jelas di dalam kelas.

Which one it means (he or she) depends entirely on context, not on the word itself. If the context has already told you the person is male or female, you’ll understand dia as “he” or “she” accordingly.

Is dia ever used for “they”, or only for one person?

In standard grammar, dia is singular (“he / she”). The usual word for “they” is mereka.

However, in informal spoken Malay, people sometimes use dia for a single person in a kind of nickname or label way, which can sound like “they” in conversational English (e.g. referring to someone without naming them), but grammatically it’s still treated as singular.

For normal learning purposes:

dia = he / she (one person)
mereka = they (more than one person)

What does the ber- prefix in bercakap do? Why not just cakap?

The prefix ber- on verbs often indicates:

an intransitive action (no direct object), or
“to be engaged in” an action or state.

Cakap by itself is the root meaning “speech / talk / to talk”.
Bercakap means “to speak / to talk (in general)”.

In many everyday contexts:

bercakap is a bit more standard or neutral,
cakap (as a verb) can sound more casual / colloquial, especially in some dialects.

In a sentence like this, dia bercakap is the normal, standard way to say “he/she speaks / is speaking”.

Is bercakap “speaks”, “is speaking”, or “spoke”? What tense is it?

Malay verbs do not change form for tense.
Bercakap just means “to speak / to talk”, without tense built into the word.

Tense is understood from context or from extra time words:

Dia bercakap dengan jelas di dalam kelas.
= He/She speaks / is speaking / spoke clearly in class (depending on context).
Tadi dia bercakap dengan jelas di dalam kelas.
= Earlier, he/she spoke clearly in class.
Esok dia akan bercakap dengan jelas di dalam kelas.
= Tomorrow he/she will speak clearly in class.

So, bercakap itself is tense‑neutral.

What is the role of dengan in dengan jelas? Could I just say dia bercakap jelas?

Dengan literally means “with”, but here it forms an adverbial phrase of manner:

dengan jelas = clearly (literally “with clarity”).

You will very often see adverbs of manner formed with dengan + adjective:

dengan perlahan = slowly
dengan kuat = loudly
dengan sopan = politely

Saying dia bercakap dengan jelas is natural and standard.

Can you say dia bercakap jelas?

In some informal speech, people might say that, and listeners will understand.
For standard / textbook Malay, dengan jelas is the safer and more idiomatic form.

What exactly does jelas mean here? Is it “clear” or “loud”?

Jelas primarily means “clear”:

clear to understand
distinct, not mumbled
easy to hear / easy to catch the words

In dengan jelas, it focuses on:

clarity of speech, not necessarily being loud.

If you specifically want “loudly”, you’d usually use something like:

dengan kuat (with strength = loudly)
dengan lantang (loudly, forcefully, ringing voice)

So dengan jelas = “clearly (understandably)”, not “loudly”.

What’s the difference between di dalam kelas and just di kelas or dalam kelas?

All three can be used, but there are slight nuances:

di dalam kelas
Literally “in inside the class”, but idiomatically “inside the classroom”.
It sounds a bit more explicit and slightly more formal. Emphasizes being inside the classroom area.
di kelas
Literally “at/in class”.
Common, slightly shorter and more casual. Often means the same as di dalam kelas in everyday usage.
dalam kelas
Literally “inside class”.
Also understood as “in the classroom / in class”. Can sound a bit elliptical; di dalam kelas is usually preferred in full sentences.

In your sentence, di dalam kelas is perfectly natural.
In many contexts, di kelas would also sound fine:

Dia bercakap dengan jelas di kelas.

Why is it di dalam, not written together as didalam?

In standard Malay spelling, di is a preposition (“at / in / on”), so it is written separately from the noun or phrase that follows:

di rumah (at home)
di sekolah (at school)
di dalam kelas (in the classroom)

It is only written together when di- is a prefix on a verb (the passive prefix), e.g.:

ditulis (is written / was written)
dibaca (is read / was read)

Here, di is a preposition, so di dalam must be two words.

Can I change the word order to Di dalam kelas, dia bercakap dengan jelas?

Yes. That is grammatically correct and natural.

Dia bercakap dengan jelas di dalam kelas.
= Neutral order: subject → verb → manner → place.
Di dalam kelas, dia bercakap dengan jelas.
= Fronts the location for emphasis or for linking with previous context (“In the classroom, he/she speaks clearly”).

Both are fine; the change is mainly about emphasis and flow, not correctness.

Are there synonyms for bercakap that I might also see?

Yes, you may encounter several verbs related to speaking:

bercakap – to talk, to speak (neutral, very common)
berbicara – to converse, to discuss, to speak (slightly more formal)
berkata – to say (usually followed by what is said or to whom)
cakap – to speak / talk (informal when used as a verb)

Examples:

Dia berbicara dengan jelas di dalam kelas.
= He/She speaks clearly in class. (more formal flavour)
Dia berkata dengan jelas kepada murid-murid.
= He/She said (it) clearly to the students.

But in your original sentence, bercakap is the most straightforward, general choice.

Can I drop the subject dia and just say Bercakap dengan jelas di dalam kelas?

You can, but it changes how the sentence feels:

Dia bercakap dengan jelas di dalam kelas.
= A full sentence with a clear subject (“He/She speaks clearly in class”).
Bercakap dengan jelas di dalam kelas.
= Grammatically it looks like an instruction / command (“Speak clearly in class”) or a fragment in a list of rules.

Malay does sometimes omit pronouns when the subject is obvious from context, but for neutral statements, you usually keep dia.
So, for a normal descriptive sentence, it’s better to keep dia.