Learn Hardcore Indonesian: Sebelum menonton teater, kami makan cepat di kafe di mana pelayan sudah hafal pesanan kami. - Before watching the theater, we eat quickly at a café where the server already knows our usual order.

Sebelum menonton teater = Before watching (the) theater / before going to the theater show
menonton is the verb to watch in its basic verb form (no subject stated in that clause; the subject is understood from context, usually the same as the main clause subject: kami).

You could also say:

Sebelum kami menonton teater, ...

Both are correct. Dropping kami is common and natural when the subject is clear.

Can I move sebelum menonton teater to the end of the sentence, like in English: “We ate quickly at the café before watching the play”?

Yes. Both word orders are correct:

Sebelum menonton teater, kami makan cepat di kafe...
Kami makan cepat di kafe sebelum menonton teater...

Differences:

Putting sebelum menonton teater at the beginning emphasizes the time/condition (what happened first).
Putting it at the end sounds a bit more neutral, like normal storytelling order.

The comma is important when it comes first:

Sebelum menonton teater, kami makan cepat... ✅
Kami makan cepat di kafe sebelum menonton teater. ✅ (no comma needed)

Does menonton teater mean “going to the theater” or specifically “watching a theater performance”?

Literally, menonton teater = to watch theater (a play).

It focuses on the watching, not the going.
In context, people will understand it as watching a theater performance / stage play, usually at some theater venue.

If you want to emphasize physically going there:

pergi ke teater = go to the theater (place)
menonton pertunjukan teater = watch a theater performance (more explicit/formal)

What exactly does makan cepat mean? Is it “eat fast food” or “eat quickly”? Why not makan dengan cepat?

In this context:

makan cepat = to eat quickly / to have a quick meal

It does not mean “fast food” (that would be makanan cepat saji or just fast food).

About forms:

makan cepat – very common in speech; the adjective cepat is used adverbially (like “eat quick” in casual English).
makan dengan cepat – more explicitly adverbial and a bit more formal/complete (“eat quickly”).
makan cepat‑cepat – sounds more urgent/emphatic: “eat in a hurry”.

All three are grammatically acceptable; makan cepat here is natural and casual.

Why is it di kafe and not ke kafe?

di = at / in / on (location)
ke = to (movement/direction)

In the sentence, the action happens at the café, not “to” the café:

kami makan cepat di kafe = we ate quickly at a café ✅

If you mention going there:

Kami pergi ke kafe lalu makan cepat di sana.
= We went to a café then ate quickly there.

How is di mana used here? Isn’t di mana normally a question word “where”?

Yes, di mana is literally where, but in this sentence it works like a relative clause marker: “where…” or “in which…”.

kafe di mana pelayan sudah hafal pesanan kami
= the café where the waiter already knows (has memorized) our order

So:

In questions:
Kafe itu di mana? = Where is that café?
In relative clauses (describing a noun):
kafe di mana pelayan sudah hafal pesanan kami
= the café where the waiter already knows our order.

You could also say, more “textbook”:

kafe yang pelayannya sudah hafal pesanan kami
(“the café whose waiter already knows our order”)

Could I replace di mana with yang here?

You can, but you must adjust the structure slightly.

Original:

kafe di mana pelayan sudah hafal pesanan kami

With yang, you’d normally include the possessive:

kafe yang pelayannya sudah hafal pesanan kami
= the café whose waiter already knows our order

Or:

kafe yang pelayannya sudah hafal pesanan kami itu (if you mean “that café in particular”)

So:

di mana feels very natural in speech and writing for “where …”.
yang is more general and can be combined with pelayannya to give the “whose waiter” meaning.

What nuance does sudah add in pelayan sudah hafal pesanan kami?

Sudah means already and shows that the action/state is:

Completed or in place before some reference time (here: before/when we eat there).

So:

pelayan hafal pesanan kami – the waiter knows our order (statement of fact).
pelayan sudah hafal pesanan kami – the waiter already knows / has already memorized our order (maybe earlier than expected, or as a result of our frequent visits).

It can imply:

we are regular customers,
the waiter has come to know our usual order over time.

What is the difference between hafal and ingat, and why use hafal here?

Both relate to memory, but they’re used differently:

hafal
- To know something by heart / from memory, often exactly and reliably.
- Used for: phone numbers, lines of a play, Qur’an verses, people’s usual orders, etc.
ingat
- To remember something (as opposed to forgetting).
- More general and doesn’t always imply exact, complete memorization.

In this context:

pelayan sudah hafal pesanan kami
= the waiter knows our order by heart / has it memorized

If you said pelayan sudah ingat pesanan kami, it’s understandable, but sounds more like “the waiter now remembers our order (this time)” rather than “has it memorized as our usual”.

What exactly does pesanan mean, and how is it formed?

Pesanan is a noun meaning order (something you order), especially in a restaurant/shop context.

It comes from the verb pesan (to order, to book/reserve):

pesan = to order / to book
pesanan = an order / a booking / a reservation

In this sentence:

pesanan kami = our order (what we normally order there)

Related forms:

memesan = to place an order / to book
memesan makanan = to order food

Why is kami used here instead of kita?

Both kami and kita mean we / us, but:

kami = we (not including the listener)
kita = we (including the listener)

In this sentence, the speaker is talking about their own group going to eat before the theater. The listener is probably not part of that group, so kami is correct.

If the speaker were talking about a plan that includes the listener (e.g. telling a friend what “we” will do together), they’d use:

Sebelum menonton teater, kita makan cepat di kafe...
= Before watching the play, we (you and I) will eat quickly at the café...

Is there another natural way to say “the café where the waiter already knows our order”?

Yes, several alternatives are natural; some sound even more idiomatic:

kafe langganan kami
- langganan = regular / usual / subscription-type customer
- kafe langganan kami = the café we’re regulars at
  (implies the staff know your usual order)
Slight rephrases:
- kafe tempat pelayan sudah hafal pesanan kami
  (“the café where the waiter already knows our order”)
- kafe yang pelayannya sudah hafal pesanan kami
  (“the café whose waiter already knows our order”)

All of these sound natural; the original with di mana is already good everyday Indonesian.

Is the whole sentence formal, informal, or neutral in style?

The sentence is neutral and natural for everyday spoken and written Indonesian:

Vocabulary (like sebelum, makan cepat, kafe, pelayan, pesanan) is common and standard.
No slang, no strong regional dialect.

It would sound fine:

in casual conversation,
in a narrative text,
or in a neutral article/story.

For very formal writing, you might see slightly more formal choices (e.g. restoran instead of kafe in some contexts, or pesanan kami sudah dihafal oleh pelayan), but that’s not necessary here.