Learn Hardcore Indonesian: Guru astronomi memberi tugas observasi bintang yang harus kami kerjakan dari halaman rumah. - The astronomy teacher gives a star-observation assignment that we must do from the yard at home.

guru = teacher
astronomi = astronomy
→ guru astronomi = astronomy teacher
memberi = to give
tugas = assignment / task
→ memberi tugas = to give an assignment
observasi = observation
bintang = star(s)
→ tugas observasi bintang = star‑observation assignment
yang = that / which (introduces a relative clause)
harus = must / have to
kami = we (excluding the listener)
kerjakan = do (work on) it (verb kerja
- suffix -kan)
dari = from
halaman = yard / yard area
rumah = house / home
→ dari halaman rumah = from the (house) yard

So the structure is:

Guru astronomi
astronomy teacher (subject)
memberi tugas observasi bintang
gave a star‑observation assignment (verb + object)
yang harus kami kerjakan
which we must do (relative clause describing tugas)
dari halaman rumah
from the house yard (location phrase modifying the relative clause)

A natural English rendering:
The astronomy teacher gave us a star‑observation assignment that we have to do from our yard at home.

Why is there no word for the in guru astronomi? How do I know it’s the astronomy teacher and not an astronomy teacher?

Indonesian usually does not mark definiteness (the/a) with a separate word like the or a in English.

guru astronomi can mean:
- an astronomy teacher
- the astronomy teacher
- just astronomy teacher (generic)

Which one is meant is determined by context, not by grammar:

In a story where a specific teacher has already been mentioned, guru astronomi will be understood as the astronomy teacher.
When first introducing such a character, English might choose an astronomy teacher, but Indonesian still just says guru astronomi.

There are ways to make something more clearly definite (e.g. guru astronomi itu = that astronomy teacher), but plain guru astronomi itself is neutral with respect to the vs a.

Can guru astronomi mean both astronomy teacher and teacher of astronomy? How do noun–noun combinations work here?

Yes. Indonesian often expresses relationships between nouns simply by putting them next to each other:

guru astronomi
- literally: teacher astronomy
- interpreted as: astronomy teacher / teacher of astronomy

This pattern is very common:

guru matematika = math teacher
buku sejarah = history book
pelatih sepak bola = soccer coach

The second noun (astronomi) describes or specifies the first noun (guru). You do not need a preposition like of:

You do not say guru dari astronomi for teacher of astronomy here; that sounds unnatural.

Could we say memberikan tugas instead of memberi tugas? What’s the difference?

Both are grammatically correct, and both can mean to give an assignment.

memberi tugas
memberikan tugas

Subtle differences:

Style and frequency
- memberi tugas is very common and slightly shorter.
- memberikan tugas sounds a bit more formal or careful, often used in writing (essays, reports).
Focus
- In many contexts, memberi and memberikan overlap so much that the difference is negligible.
- Technically, -kan can emphasize the effect on the object (tugas), but in everyday use here it does not strongly change the meaning.

You could rewrite the beginning of the sentence as:

Guru astronomi memberi tugas observasi bintang …
Guru astronomi memberikan tugas observasi bintang …

Both are fine and natural.

Is observasi here a noun or a verb? Could we say something like pengamatan or mengamati instead?

In tugas observasi bintang, observasi is functioning as a noun:

observasi = observation (noun, often a loanword from English)
tugas observasi bintang = an assignment of star observation / a star observation assignment

Alternatives:

tugas pengamatan bintang
- pengamatan = observation (native‑style noun from amat = observe)
- This sounds slightly more formal or more in line with scientific Indonesian.
To use a verb, you might say:
- tugas untuk mengamati bintang = an assignment to observe stars
- mengamati = to observe

So your options include:

tugas observasi bintang (loanword noun)
tugas pengamatan bintang (native-style noun)
tugas untuk mengamati bintang (verb construction)

All are understandable; choice depends on style and context.

What does yang do in yang harus kami kerjakan?

yang introduces a relative clause, similar to that or which in English.

Structure:

tugas observasi bintang
star‑observation assignment
yang harus kami kerjakan
which we must do

So the full chunk:

tugas observasi bintang yang harus kami kerjakan
= the star‑observation assignment that we must do

Function of yang:

It marks that what follows is a clause describing tugas observasi bintang.
Without yang, it would be confusing:
tugas observasi bintang harus kami kerjakan is grammatical, but changes rhythm/focus; yang makes the relative structure very clear.

In short, yang here works like English that/which linking the noun to its descriptive clause.

Why is it harus kami kerjakan and not kami harus kerjakan or kami harus mengerjakan?

All of these exist, but they have different structures and uses.

harus kami kerjakan (the one in your sentence)
- This is inside a relative clause describing tugas:
  - tugas … yang harus kami kerjakan
  - literally: assignment which must we do
- In this pattern, it’s common to place harus before the subject:
  - yang harus kami kerjakan
  - yang harus mereka lakukan (that they must do)
kami harus mengerjakan tugas observasi bintang
- This is a full main clause:
  - kami = we
  - harus = must
  - mengerjakan tugas … = do the assignment …
- This would be a stand‑alone sentence:
  We must do the star‑observation assignment…
kami harus kerjakan
- In casual speech, you might hear kami harus kerjakan tugas itu, but in a relative clause the pattern yang harus kami kerjakan is the natural one.
- kami harus kerjakan on its own sounds incomplete unless you say what you must do:
  kami harus kerjakan tugas itu.

So:

As a descriptive phrase attached to tugas, the standard form is yang harus kami kerjakan.
As an independent statement, you’d use kami harus mengerjakan (tugas itu).

What is the role of the suffix -kan in kerjakan? Why not just kerja?

Base word:

kerja = to work; work (verb or noun)

With meN- and -kan:

mengerjakan = to do / to work on something (transitive verb: takes an object)
- e.g. mengerjakan tugas = to do an assignment

In yang harus kami kerjakan, the meN- prefix is dropped because of the structure:

Full underlying form: yang harus kami mengerjakan [tugas itu]
But Indonesian almost never keeps meN- here; instead, it moves the verb after the subject and drops meN-:
- yang harus kami kerjakan [tugas itu]

So kerjakan here is:

a transitive form of kerja: to do (it)
still implies an object (tugas observasi bintang) even though it’s not repeated.

You would not say yang harus kami kerja in standard Indonesian; that sounds incomplete or non‑standard. The -kan is needed to make it the “do something” sense, not just “work in general”.

Why is kami used here instead of kita? What’s the nuance?

Indonesian distinguishes two kinds of we:

kami = we (excluding the listener)
kita = we (including the listener)

In this sentence:

yang harus kami kerjakan implies:
- the assignment that we (students) have to do,
- generally excluding the person being spoken to (maybe the teacher, or someone else not doing the assignment).

If the speaker included the listener among the people who must do the assignment, they might use kita:

… yang harus kita kerjakan …
= that we (you and I, all of us) must do …

So kami here signals that the group who must do the assignment does not include the person being addressed.

Does dari halaman rumah describe where we physically do the homework, or where we observe the stars from?

Grammatically, dari halaman rumah is attached to the whole clause yang harus kami kerjakan, but in terms of meaning it clearly refers to the location of the observation, not where you sit to write the report.

Natural interpretation:

We must carry out the observation from the yard at home.
The work (observation) must be done from that vantage point.

So:

tugas observasi bintang yang harus kami kerjakan dari halaman rumah
= an assignment to observe stars that we must carry out from our yard at home.

If you wanted to be extra explicit about observing from there, you could say:

… tugas observasi bintang dari halaman rumah yang harus kami kerjakan.
(but the original is already clear in context)

How do we know it means our yard/house when it just says halaman rumah, without -ku or kami?

Indonesian often leaves possession implicit when it’s obvious from context.

halaman rumah literally = the house yard or the yard of a house.
In this context (students getting homework to do from a house yard), the natural assumption is the students’ own home, i.e. our yard at home.

If you really want to specify:

halaman rumah kami = our house’s yard
halaman rumah saya = my house’s yard

But because that’s usually understood, people often just say dari halaman rumah, especially when talking about typical homework that you do from your own home.

Is this sentence formal, informal, or neutral? How would it sound in casual conversation?

The sentence is mostly neutral–formal, suitable for:

written instructions or descriptions
classroom contexts
storytelling with a neutral tone

In casual spoken Indonesian, people might simplify or rearrange it, for example:

Guru astronomi kasih kami tugas buat observasi bintang dari halaman rumah.
- kasih instead of memberi
- buat instead of yang harus (less precise, but common)

Or:

Guru astronomi kasih tugas observasi bintang. Kita harus ngerjainnya dari halaman rumah.
- Split into two sentences
- ngerjainnya (colloquial for mengerjakannya)

Your original sentence is perfect for textbooks, written stories, or a teacher’s explanation.

If there’s no tense marking, how do we know this means gave (past) instead of gives or is giving?

Indonesian verbs generally do not change form for tense. memberi by itself can mean:

gives
gave
is giving
will give

Which one is intended depends entirely on context (time expressions, surrounding sentences, the situation).

In your isolated sentence:

Guru astronomi memberi tugas … could be translated as:
- The astronomy teacher gives an assignment… (habitually)
- The astronomy teacher gave an assignment… (past event)

A textbook or story might translate it as gave simply because the broader narrative is in the past. If you wanted to explicitly mark past, you could add an adverb:

Kemarin guru astronomi memberi tugas …
= Yesterday the astronomy teacher gave an assignment …

But grammatically, the verb form memberi itself is neutral with respect to tense.