Learn Hardcore Indonesian: Kami membahas rencana liburan di ruang tamu. - We discuss the vacation plan in the living room.

So Kami membahas rencana liburan di ruang tamu implies that the speaker and some others were discussing the holiday plans, but the listener was not part of that group.

If the listener was also involved in the discussion, you would say:

Kita membahas rencana liburan di ruang tamu.

What does membahas mean exactly, and how is it related to bahas?

The base word is bahas, which means to discuss / to talk about something in a focused way (often a bit more serious or systematic than just casual chatting).

Membahas = meN- prefix + bahas.
The meN- prefix turns it into an active transitive verb: to discuss (something).

So:

bahas → root form (dictionary form)
membahas → standard active form used in full sentences:
- Kami membahas rencana liburan. = We discuss / are discussing the holiday plan.

Is it correct to say Kami bahas rencana liburan di ruang tamu without mem-?

In informal spoken Indonesian, Kami bahas rencana liburan di ruang tamu is very common and sounds natural.

However, in standard / formal Indonesian, the grammatically complete form is Kami membahas rencana liburan di ruang tamu.

So:

Talking with friends: Kami bahas rencana liburan… → fine, casual.
Writing an essay, report, or exam: prefer Kami membahas rencana liburan…

Do I need the preposition tentang after membahas, like membahas tentang rencana liburan?

You do not need tentang here.

membahas sesuatu already means to discuss something, so
- Kami membahas rencana liburan is already complete and correct.

You might hear membahas tentang… in everyday speech, and many native speakers say it, but in careful or formal language it’s often considered redundant.

For learners, the safest and most correct pattern is:

membahas + object
- membahas rencana liburan
- membahas masalah ini

What is the literal meaning of rencana liburan, and could I also say rencana untuk liburan?

Literally:

rencana = plan
liburan = holiday / vacation

So rencana liburan = holiday plan / vacation plan.

You can say rencana untuk liburan (plan for the holiday), and it is understandable, but:

rencana liburan is simpler and more natural in most contexts.
rencana untuk liburan can feel a bit heavier or more specific, like a plan that serves the purpose of a holiday.

For everyday speech, stick with rencana liburan.

How would I change the tense, like we were discussing or we will discuss?

Indonesian verbs don’t change form for tense. You add time words or aspect markers instead.

Using this sentence:

Past (we were discussing / we discussed)
- Tadi kami membahas rencana liburan di ruang tamu.
  (tadi = earlier / just now)
- Kemarin kami membahas rencana liburan di ruang tamu.
  (kemarin = yesterday)
Progressive (we are / were in the middle of discussing)
- Kami sedang membahas rencana liburan di ruang tamu.
  (sedang = in the process of)
Future (we will discuss)
- Kami akan membahas rencana liburan di ruang tamu.
  (akan = will)
- Nanti kami membahas rencana liburan di ruang tamu.
  (nanti = later; often used instead of akan in everyday speech)

Can I omit kami and just say Membahas rencana liburan di ruang tamu?

Yes, Indonesian often drops the subject when it’s clear from context.

Membahas rencana liburan di ruang tamu could mean:

(We/they/people) are discussing the holiday plan in the living room.

However:

In writing or when context is not clear, it’s better to keep kami.
In a conversation where it’s obvious you’re talking about yourself and your group, dropping kami is natural.

What does di mean here, and how is it different from ke and dari?

These are common prepositions of place:

di = in / at / on (location, static)
- di ruang tamu = in the living room
ke = to (movement towards)
- ke ruang tamu = to the living room
dari = from (movement away, origin)
- dari ruang tamu = from the living room

In this sentence, the action is happening in the living room, not moving there, so di is correct.

Is di ruang tamu more like in the living room or at the living room?

In natural English, di ruang tamu is almost always translated as in the living room.

English rarely says at the living room; at is used more with:

at home, at school, at the office

For a specific room inside a house, in is normally used:

in the living room
in the kitchen

What exactly is ruang tamu? Is it the same as a living room in English?

Literally:

ruang = room / space
tamu = guest

So ruang tamu literally means guest room, but in most everyday contexts it corresponds to the living room or sitting room where you receive guests and spend time with family.

Some houses may distinguish:

ruang tamu = more formal front room to receive guests
ruang keluarga = family room, more private

But often ruang tamu is used broadly for the main sitting/living area.

Can I change the word order, like Di ruang tamu, kami membahas rencana liburan?

Yes, that word order is correct and natural.

Kami membahas rencana liburan di ruang tamu.
- Neutral order; focus more on the activity.
Di ruang tamu, kami membahas rencana liburan.
- Slightly emphasizes the location di ruang tamu (in the living room).

Both are grammatically fine; the difference is mostly in emphasis and style.

Is there any difference between liburan and cuti in this context?

Yes, they’re related to time off, but not identical:

liburan = holiday / vacation in a general sense
- school holidays, family vacations, etc.
- rencana liburan = holiday plan / vacation plan
cuti = leave from work, usually official / paid leave
- cuti tahunan = annual leave
- cuti melahirkan = maternity leave

So rencana liburan is the right phrase here. You might hear rencana cuti if you specifically mean planning your leave days at work, but that’s a bit narrower.