Learn Hardcore Indonesian: Mesin cuci itu dipakai dua kali seminggu ketika cucian sudah menumpuk. - That washing machine is used twice a week when the laundry has piled up.

Why is there no word like is/are in this sentence? In English we’d say “The washing machine is used…” but Indonesian just says “Mesin cuci itu dipakai…”.

Indonesian normally does not use a separate verb like to be (is/are/am) before verbs or adjectives.

In English: The washing machine is used…
In Indonesian: Mesin cuci itu dipakai…

Here dipakai already functions as the verb (is used), so nothing like “adalah” or “itu adalah dipakai” is needed, and in fact that would be wrong here.

You only see adalah before nouns (e.g. Dia adalah guru = He is a teacher), not before a verb like dipakai.

What does itu add in mesin cuci itu? Why not just mesin cuci?

Itu is a demonstrative, roughly that / the depending on context.

mesin cuci = a washing machine / washing machine (general)
mesin cuci itu = that washing machine / the washing machine (a specific one the speakers have in mind)

By using itu, the speaker implies:

we’re talking about a particular washing machine (e.g., the one at home),
not washing machines in general.

Leaving it out would make the sentence sound more generic or less specific about which washing machine.

Why is dipakai (passive) used here instead of an active form like memakai?

In Indonesian, the passive is very common, especially when:

the object is more important than the person doing the action, or
the doer is obvious from context (e.g., the family at home).

Mesin cuci itu dipakai… literally:
That washing machine is used…

If you make it active, you’d say:

Kami memakai mesin cuci itu…
We use that washing machine…

Both are grammatical. The passive version:

keeps the focus on mesin cuci itu (the washing machine),
feels very natural in descriptive statements.

If you really want to mention who uses it in passive, you can add oleh:

Mesin cuci itu dipakai oleh kami…
That washing machine is used by us…

But usually oleh + pronoun is omitted when it’s obvious.

How is dua kali seminggu structured, and can I say dua kali dalam seminggu or dua kali per minggu?

dua kali seminggu is literally:

dua kali = two times / twice
seminggu = (in) a week

So it means twice a week.

Alternative forms:

dua kali dalam seminggu – also correct, a bit more explicit, literally two times within a week.
dua kali per minggu – also used, sounds a bit more formal or “counting-like”.
You’ll also hear dua kali seminggu very often in speech; it’s short and very natural.

All three are acceptable; dua kali seminggu is the most everyday-sounding.

What does ketika do here? How is it different from saat or kalau?

ketika is a conjunction meaning when (for a time clause).

In this sentence, ketika cucian sudah menumpuk = when the laundry has piled up.

Compare:

ketika – neutral “when” in time clauses, works in spoken and written Indonesian.
saat – also “when/at the time (that)”, slightly more formal/literary but very common in speech too.
kalau – often means if, but also widely used as when in everyday speech, especially for repeated/habitual events.

Here, you could also hear:

… dua kali seminggu saat cucian sudah menumpuk.
… dua kali seminggu kalau cucian sudah menumpuk. (more colloquial)

ketika is a safe, neutral choice.

Could I put the ketika-clause at the beginning, like in English “When the laundry has piled up, the washing machine is used…”?

Yes. Both orders are possible:

Mesin cuci itu dipakai dua kali seminggu ketika cucian sudah menumpuk.
Ketika cucian sudah menumpuk, mesin cuci itu dipakai dua kali seminggu.

Notes:

In writing, if the ketika-clause comes first, you typically put a comma after it.
The meaning doesn’t change; it’s just a different information order, just like in English.

What exactly is cucian? How is it related to cuci, and how is it different from pakaian or baju kotor?

cuci is the verb root to wash (especially laundry).
cucian is formed with the suffix -an:
- cucian = things to be washed / washed items, and in context usually laundry.

So:

cucian ≈ laundry.
pakaian = clothes (in general, not necessarily dirty).
baju kotor = literally dirty clothes, very explicitly “clothes that are dirty”.

In this sentence, cucian naturally means the dirty laundry that’s waiting to be washed.

What does sudah add in cucian sudah menumpuk? Could I just say cucian menumpuk?

sudah literally means already, but often functions as a marker that something has reached a certain state or is now the case.

cucian menumpuk = the laundry piles up / is piling up.
cucian sudah menumpuk = the laundry has already piled up / has built up.

Nuance:

sudah suggests the situation has reached a noticeable/late point, often implying “it’s too much / it’s time to do something about it now”.
Without sudah, it’s more neutral and less “late”.

So here sudah supports the idea: “Once the laundry has really piled up (enough), then the machine gets used.”

What does menumpuk really mean here? Is it just “a lot of laundry”?

menumpuk comes from tumpuk (pile/stack) and means to pile up / to accumulate / to form a pile.

In this context:

cucian sudah menumpuk = the laundry has piled up; there are piles of laundry.

It doesn’t just mean “much”:

banyak cucian = a lot of laundry (quantity).
cucian sudah menumpuk = the laundry has physically accumulated into piles, with an implied sense of being overdue or neglected a bit.

How would I say this sentence in a more active way, explicitly showing “we use the washing machine…”?

You can switch to the active voice:

Kami memakai mesin cuci itu dua kali seminggu ketika cucian sudah menumpuk.
Or if it’s a family: Kami sekeluarga memakai mesin cuci itu dua kali seminggu ketika cucian sudah menumpuk.

Here:

kami = we (excluding the person you’re talking to).
memakai = to use (active).
The rest of the structure stays the same.

Both active and passive versions are natural:

Passive: Mesin cuci itu dipakai… (focus on the washing machine)
Active: Kami memakai mesin cuci itu… (focus on the users)

How is tense shown here? Dipakai looks like “is used”, but how would I say “was used” or “will be used”?

Indonesian verbs like dipakai don’t change form for tense. Time is usually shown by:

context, and/or
time words (yesterday, later, tomorrow, etc.).

For example:

Kemarin mesin cuci itu dipakai dua kali.
Yesterday, the washing machine was used twice.
Besok mesin cuci itu akan dipakai dua kali.
Tomorrow, the washing machine will be used twice.

Here:

kemarin = yesterday (past)
besok = tomorrow (future)
akan = will (optional, but clarifies future)

In the original, dipakai dua kali seminggu naturally suggests a habitual action (is used twice a week).

Is there any difference in nuance between dipakai and digunakan for “used” here?

Both are correct and very similar in meaning:

dipakai – from pakai (to use), very common and everyday.
digunakan – from guna (use/function), a bit more formal or neutral, often seen in written language, instructions, etc.

So you could say:

Mesin cuci itu dipakai dua kali seminggu… (colloquial, natural)
Mesin cuci itu digunakan dua kali seminggu… (slightly more formal)

For casual spoken Indonesian, dipakai is perfectly natural.