Learn Hardcore Indonesian: Sejak tahun lalu, kami tinggal di rumah kecil di utara kota. - Since last year, we have been living in a small house in the north of the city.

kami = we (excluding the listener). The speaker’s group, not including you.
kita = we (including the listener).
If the speaker means “you and I live…,” use kita: Sejak tahun lalu, kita tinggal… Otherwise, kami is correct here.

Does tinggal mean “to live” permanently, or can it also mean “to stay” temporarily?

tinggal covers both “live/reside” and “stay.” Context decides.
For clearly permanent residence, you can also use menetap or bermukim (more formal): Sejak tahun lalu, kami menetap…

Do I need sudah or telah with sejak to express “have been living”?

Not required. Sejak already signals a state that started in the past and continues now.
Adding sudah is common but optional: Sejak tahun lalu, kami sudah tinggal… (emphasizes the state has started).
telah is formal/press style; with ongoing states it can sound formal or stiff. In everyday speech, prefer no marker or sudah.

Can I say dari tahun lalu or mulai tahun lalu instead of sejak tahun lalu?

Best choice for “since” is sejak.
mulai tahun lalu is acceptable and emphasizes the starting point: Mulai tahun lalu, kami tinggal…
dari tahun lalu is heard colloquially; to be clear, many add an endpoint: Dari tahun lalu sampai sekarang…
Avoid the redundant dari sejak.

Where can I put the time phrase, and is the comma necessary?

Position: Beginning or end both work.
- Sejak tahun lalu, kami tinggal…
- Kami tinggal… sejak tahun lalu.
Comma: Optional after a fronted time phrase; it marks a natural pause.

Why is di used twice (di rumah kecil di utara kota)?

di marks static location. You have two nested locations:
- live in a small house (di rumah kecil)
- that’s in/to the north of the city (di utara kota)
Don’t use ke here; ke is for movement.

What does di utara kota mean exactly—inside the city’s northern part, or outside the city to its north?

It’s often ambiguous and context decides.
To be clear:
- Inside the city’s northern area: di bagian utara kota or, for a named city, di Jakarta Utara.
- Outside the city, to its north: di sebelah utara kota or, with a name, di utara Jakarta.
Example contrasts:
- Kami tinggal di bagian utara kota. (within the city)
- Kami tinggal di sebelah utara kota. (outside, to the north)

Is the adjective order right in rumah kecil? Why not kecil rumah?

In Indonesian, adjectives typically follow nouns: rumah kecil (“small house”).
You can add yang for emphasis/specificity: rumah yang kecil (“the house that is small”).

Do I need an article like “a,” e.g., sebuah rumah kecil?

Does kota need something like “the” (kota ini/itu)?

No articles. kota can mean “the city” by context (often the city already known to both speakers).
To be explicit, say kota ini, kota itu, or name it: di utara Jakarta.

Can I omit the second di and say “rumah kecil utara kota”?

No. You need di before each separate location phrase. Say di rumah kecil di utara kota.

Is tahun lalu the only way to say “last year”?

Should utara be capitalized?

Not in this sentence. Cardinal directions (utara, selatan, etc.) are lowercase unless part of a proper name: Jakarta Utara, Kalimantan Timur.

If I want a more formal or careful style overall, what could I say?

Sejak tahun lalu, kami menetap di sebuah rumah kecil di bagian utara kota.
Very formal: Sejak tahun lalu, kami bertempat tinggal di sebuah rumah kecil di bagian utara kota.