Learn Hardcore Indonesian: Mantan pacarnya suka membahas spoiler film di grup chat, jadi sekarang dia mematikan notifikasinya. - His/Her ex likes to talk about movie spoilers in the chat group, so now he/she turns off the notifications.

mantan = ex-, former
pacar = boyfriend/girlfriend (gender‑neutral)
-nya = his/her/their (3rd person) or sometimes the (definite marker)

In this sentence, -nya is possessive, so mantan pacarnya = his/her ex (partner).

By context, -nya refers to dia (the person in the second clause). So:

Mantan pacarnya = his/her ex
dia = he/she (the one whose ex it is)

Could mantan pacarnya also mean the ex (boyfriend/girlfriend), not necessarily “his/her ex”?

Yes, -nya can also act like a definite article (the). So in isolation:

mantan pacarnya could be understood as the ex (boyfriend/girlfriend)

However, because the sentence later has dia (he/she) and the story is about what this person does (turns off notifications because of that ex), the natural reading here is his/her ex rather than just the ex in general.

Why do we use suka membahas instead of just membahas? What does suka add?

Suka literally means to like, but in front of a verb it often shows habit or tendency:

membahas spoiler film = discusses movie spoilers
suka membahas spoiler film = likes to / often / tends to discuss movie spoilers

So suka here means the ex habitually does this, not just once. It’s similar to:

He’s always talking about movie spoilers
He tends to talk about movie spoilers

Can suka really be followed by a verb like membahas? I thought suka only took nouns.

In everyday Indonesian, suka + verb is very common and natural.

Saya suka kopi. = I like coffee.
Saya suka membaca. = I like to read / I enjoy reading.

So:

suka membahas = likes to discuss / enjoys discussing

This is completely normal and widely used.

What’s the nuance of membahas compared to something like membicarakan or ngomongin?

All can relate to talking about something, but:

membahas (from bahas) = to discuss, often sounds a bit more systematic / in-depth than just casual chatter.
membicarakan (from bicara) = to talk about / discuss, fairly neutral.
ngomongin (colloquial from ngomongin < ngomong) = to talk about, casual, often used in speech.

In this casual social context, membahas spoiler film implies the ex brings up and talks about spoilers as a topic, not just mentions them in passing.

Why is it spoiler film and not spoiler filmnya or some plural form?

A few points:

spoiler is a borrowed English word; Indonesian usually doesn’t mark plural using s.
spoiler film = movie spoilers in general (no need to mark plural).
spoiler filmnya would mean the movie’s spoilers / the spoilers of that movie (more specific, referring to a particular film already known in context).

Here, spoiler film is general: they like talking about movie spoilers (not just for one specific movie).

Why do we say di grup chat? Is grup chat just English inside Indonesian?

Yes, grup chat is a loan phrase from English and is very common in informal Indonesian, especially for online messaging.

di grup chat = in the group chat

Alternatives (a bit more Indonesian, but still common):

di grup (if context is clear that it’s a chat group, e.g., WhatsApp group)
di grup obrolan (more literally “in the chat group / conversation group”)

Using the English loan grup chat is very natural in daily speech and text.

What does jadi mean here? Is it the same jadi as in “become”?

Indonesian jadi has two main uses:

Lexical verb: become / turn into
- Air jadi es. = The water becomes ice.
Conjunction: so / therefore / as a result
- Dia sibuk, jadi dia tidak datang. = He’s busy, so he didn’t come.

In the sentence:

... di grup chat, jadi sekarang dia mematikan notifikasinya.

jadi is a conjunction meaning so / therefore:
… in the group chat, so now he/she turns off the notifications.

How do we know the tense? Does mematikan notifikasinya mean “turns off” or “has turned off”?

Indonesian does not mark tense grammatically (no verb endings for past/present/future). Time/aspect is inferred from context and time words.

Here:

sekarang = now
mematikan notifikasinya is neutral in tense.

Depending on context, natural English translations could be:

… so now he/she turns off the notifications.
… so now he/she has turned off the notifications.
… so now he/she is turning off the notifications.

All of those are compatible with the Indonesian sentence.

What does mematikan literally mean, and how is it formed?

Mematikan comes from:

mati = dead / off
prefix meN-
- root mati
  - suffix -kan

mematikan = to turn something off / to switch something off / to make something dead/off.

So:

mematikan lampu = to turn off the light
mematikan ponsel = to turn off the phone
mematikan notifikasinya = to turn off the notifications (or his/her notifications, depending on reading)

What exactly is notifikasinya? Is -nya “his/her” or “the”?

Notifikasinya = notifikasi + -nya.

notifikasi = notification(s) (loan from English)
-nya can be:
- his/her/their/its (possessive), or
- the (definite marker)

So mematikan notifikasinya can mean:

to turn off his/her notifications (possessive), or
to turn off the notifications (definite, referring to the ones from that group chat).

In this context, both readings fit, and they amount to the same idea: turning off the notifications from that group chat.

Is dia male or female? How would you say specifically “his ex-girlfriend” or “her ex-boyfriend”?

Dia is gender-neutral in Indonesian. It can mean he or she.

To be more specific:

mantan pacar laki-laki / mantan pacar cowok = ex-boyfriend
mantan pacar perempuan / mantan pacar cewek = ex-girlfriend

For example:

Mantan pacar cowoknya suka membahas spoiler film… = Her ex-boyfriend likes to talk about movie spoilers… (here context suggests the owner is female)
Mantan pacar ceweknya suka membahas spoiler film… = His ex-girlfriend likes to talk about movie spoilers…

In everyday speech, people often rely on context rather than marking the gender explicitly.