Apa yang dia jelaskan tadi tentang sejarah agak rumit.

What he/she explained earlier about history is rather complicated.

Breakdown of Apa yang dia jelaskan tadi tentang sejarah agak rumit.

• dia: he/she
• adalah: to be
• tentang: about
• sejarah: the history
• tadi: earlier
• agak: rather
• yang: that/which
• apa: what
• jelaskan: to explain
• rumit: complicated

Questions & Answers about Apa yang dia jelaskan tadi tentang sejarah agak rumit.

Since the sentence starts with Apa, isn’t it a question? How can it be a statement?

In Malay, apa can be:

1. A question word (what?), or
2. Part of a noun phrase meaning “what(ever) that / the thing that”.

In Apa yang dia jelaskan tadi tentang sejarah agak rumit, the whole chunk
Apa yang dia jelaskan tadi tentang sejarah means:

“What he explained earlier about history / The explanation he gave earlier about history”

That whole chunk is the subject, and agak rumit (rather complicated) is the comment/predicate.

You can see the difference like this:

• Question:
  Apa yang dia jelaskan tadi tentang sejarah?
  = What did he explain earlier about history?

• Statement (your sentence):
  Apa yang dia jelaskan tadi tentang sejarah agak rumit.
  = What he explained earlier about history was rather complicated.

So it’s not a question because apa here is not being used as a question word; it’s part of a longer noun phrase that functions as the subject of the sentence.

What exactly is the role of yang in Apa yang dia jelaskan tadi…? Can I drop it and say Apa dia jelaskan tadi…?

Yang is a relative marker. It introduces a clause that describes or defines a noun (or a pronoun like apa).

In your sentence:

• apa = what / the thing
• yang dia jelaskan tadi tentang sejarah = that he explained earlier about history

Together:
Apa yang dia jelaskan tadi tentang sejarah
= “What he explained earlier about history / The thing that he explained earlier about history”

Without yang, the sentence Apa dia jelaskan tadi tentang sejarah agak rumit sounds ungrammatical or very non‑standard in most contexts.

General pattern:

• apa yang + clause = what that … / the thing that …
  • Apa yang kamu mahu? = What do you want?
  • Saya tak faham apa yang kamu maksudkan. = I don’t understand what you mean.

So:

• In standard Malay, you need yang here.
• In some informal speech, people may shorten things like Apa dia buat tadi?, but in a longer, more complex sentence like yours, yang is normally required.

Which part of the sentence is the subject, and which part is the predicate?

Break it up like this:

• Subject (a big noun phrase):
  Apa yang dia jelaskan tadi tentang sejarah
  = What he explained earlier about history / The explanation he gave earlier about history

• Predicate (comment about that subject):
  agak rumit
  = is rather complicated

So structurally it’s like English:

[What he explained earlier about history] [was rather complicated].

What does tadi mean exactly, and how “recent” is it? Could it go in a different position?

Tadi is a time word meaning earlier / just now / a short while ago. It usually refers to something not long before the moment of speaking—earlier today or very recently.

In your sentence:

• dia jelaskan tadi = he/she explained (it) earlier / just now

Typical nuances:

• tadi = earlier (today) / just now – fairly recent
• sebentar tadi = just a short while ago – even more recent / specific
• dulu = in the past (not necessarily recent)

Position:

• Apa yang dia jelaskan tadi tentang sejarah agak rumit.
• Apa yang dia jelaskan tentang sejarah tadi agak rumit.

Both are acceptable. Roughly:

• jelaskan tadi tentang sejarah
  → focus slightly more on the act of explaining earlier.
• jelaskan tentang sejarah tadi
  → focus slightly more on the history explanation that happened earlier.

The difference is subtle; both are natural. You usually put tadi after the main verb phrase or the phrase you want to time‑stamp.

What does agak mean here, and how strong is it compared to other words like sangat or cukup?

Agak is a degree word meaning rather, quite, somewhat. It softens the adjective.

• agak rumit = rather complicated / quite complicated / somewhat complicated
• It suggests noticeable difficulty, but not the strongest possible.

Comparison:

• sangat rumit / amat rumit = very complicated (stronger)
• terlalu rumit = too complicated (excessive)
• cukup rumit = sufficiently / quite complicated (context‑dependent)

You can omit agak:

• Apa yang dia jelaskan tadi tentang sejarah rumit.
  = What he explained earlier about history is complicated.
  (Sounds more direct/stronger.)

With agak, it feels more neutral or modest in tone.

Why is there no adalah or ialah between the subject and agak rumit?

In Malay, you often do not need a linking verb (like English “is / was”) between a noun phrase subject and an adjective.

So both of these are fine:

• Apa yang dia jelaskan tadi tentang sejarah agak rumit.
• Penjelasan dia tadi tentang sejarah agak rumit.

You could say:

• Apa yang dia jelaskan tadi tentang sejarah itu adalah agak rumit.

…but:

• Adding itu makes it more specific / emphatic (that thing he explained).
• Using adalah here is possible but more formal and a bit heavier in style; many speakers would simply omit it.

General rule of thumb:

• Between noun phrase + adjective, it’s very common to omit adalah/ialah:
  • Cuaca hari ini panas. = The weather today is hot.
  • Masalah ini serius. = This problem is serious.

Use adalah/ialah more in formal writing, especially before nouns or longer explanations, not before simple adjectives.

What is the difference between jelas, jelaskan, and menjelaskan?

They’re related but have different functions:

1. jelas

   • Basic meaning: clear (adjective) or clear/obvious (can function a bit like a verb: “to be clear”).
   • Examples:
     
     • Penjelasannya tidak jelas. = His/Her explanation is not clear.
     • Sekarang sudah jelas. = Now it’s clear.

2. jelaskan

   • From jelas + -kan → a transitive verb: to explain (something).
   • Focus on causing something to be clear.
   • Example (like your sentence):
     
     • Dia jelaskan tentang sejarah. = He/She explained about history.

3. menjelaskan

   • meN- + jelas + -kan → also a transitive verb, more standard/complete form.
   • Often interchangeable with jelaskan, especially in writing or more formal speech.
   • Examples:
     
     • Dia menjelaskan sejarah negara itu.
     • Guru menjelaskan pelajaran dengan baik.

So in your sentence, you could also say:

• Apa yang dia jelaskan tadi tentang sejarah agak rumit. (perfectly normal)
• Apa yang dia jelaskan tadi tentang sejarah agak rumit. (some speakers prefer menjelaskan in more formal contexts)

The meaning is basically the same: to explain (something).

What does tentang do here, and how is it different from mengenai or pasal?

Tentang is a preposition meaning about / regarding / concerning.

In your sentence:

• tentang sejarah = about history

Common near‑synonyms:

1. mengenai – about / regarding

   • Often a bit more formal than tentang.
   • Apa yang dia jelaskan tadi mengenai sejarah agak rumit.

2. pasal – about / regarding

   • More colloquial / informal, common in everyday speech.
   • Apa yang dia jelaskan tadi pasal sejarah agak rumit.

Rough guide:

• Formal writing: mengenai, tentang
• Neutral: tentang
• Informal speech: pasal, pasal pasal (very colloquial in some dialects)

All three can be followed by a noun phrase: tentang X, mengenai X, pasal X.

Does dia mean “he” or “she”? Is there a difference in formality?

Dia is gender‑neutral:

• It can mean he or she.
• Context tells you which one is intended, or you just leave it ambiguous.

Formality:

• dia – neutral, used in almost all everyday situations.
• beliau – more formal / respectful, used for respected people, older persons, officials, teachers, etc.
  
  • Apa yang beliau jelaskan tadi tentang sejarah agak rumit.

There’s no change in the verb; only the pronoun changes.

Can I move tadi so it comes after sejarah, like Apa yang dia jelaskan tentang sejarah tadi agak rumit? Is that still correct?

Yes, that is still correct:

• Apa yang dia jelaskan tadi tentang sejarah agak rumit.
• Apa yang dia jelaskan tentang sejarah tadi agak rumit.

Both are grammatical and natural. The difference is slight:

• jelaskan tadi tentang sejarah – “(he) earlier explained about history” (time a bit more tied to the act of explaining)
• jelaskan tentang sejarah tadi – “(he) explained about that history earlier” or “that history explanation earlier” (time a bit more tied to that topic/event)

In practice, speakers use both, and most of the time there’s no meaningful difference; it’s more about flow and emphasis than strict grammar.

Could I rephrase this with a more “concrete” noun, like penjelasan, instead of using Apa yang dia jelaskan…? Would that change the meaning?

Yes, a very natural alternative is:

• Penjelasan dia tadi tentang sejarah agak rumit.
  = His/Her explanation earlier about history was rather complicated.

Comparison:

• Apa yang dia jelaskan tadi tentang sejarah agak rumit.

  • Literally: “What he explained earlier about history was rather complicated.”
  • Uses a clause with apa yang as the subject.

• Penjelasan dia tadi tentang sejarah agak rumit.

  • Literally: “His/Her explanation earlier about history was rather complicated.”
  • Uses a noun penjelasan (explanation) as the subject.

Meaning in context is basically the same; the second sounds a bit more straightforward and “noun‑based,” while Apa yang dia jelaskan… feels a bit more like “that thing he explained…” and is also very common in speech and writing.

Is this sentence more formal or informal? Would I say it in everyday conversation?

The sentence as it stands is neutral; you could use it in both:

• Everyday speech (especially in a slightly careful or polite style), and
• Fairly neutral writing (e.g. essays, reports, explanations).

To make it more informal/spoken, you might hear:

• Apa yang dia terangkan tadi pasal sejarah agak rumit.
• Apa yang dia cakap tadi pasal sejarah agak rumit.
  
  • terangkan / cakap = more colloquial verbs
  • pasal instead of tentang

To make it more formal, you might hear or write:

• Apa yang beliau jelaskan tadi mengenai sejarah agak rumit.
• Penjelasan beliau tadi mengenai sejarah agak rumit.

Your original sentence sits comfortably in the middle: natural for a wide range of contexts.