In Colloquial Jakartan Indonesian ngapain, based on apa ‘what’, usually means ‘What (are you) doing?’:
Elu ngapain di sini?
you do.what at here
What are you doing here?
Hari Sabtu kita mau ngapain dong?
day Saturday we want do.what dp
What are we going to do on Saturday, then?
In a statement it means ‘do anything; do whatever’:
Dia mau ngapain terserah.
he want do.what up.to.him
Whatever he wants to do it’s up to him.
This form, which is very frequent in Colloquial Jakartan Indonesian speech, is a rather unique informal word, having as it does the otherwise transitive suffix-in. It ‘should’ correspond to Formal Indonesian mengapakan, a transitive verb meaning ‘do what to someone/something’. Instead it corresponds to more formal (sedang) apa? ‘(at present) doing what?’.
In some contexts it can be translated ‘why?; what for?’, as well as ‘What (are you)doing?’:
Elu ngapain sih bolak-balik mulu?
you do.what dp back.and.forth only
What are you just going back and forth for?
Gua udah punya Wati; ngapain gue ngeliat yang lain?
I already have W do.what I look.at which other
I have Wati(girl’s name) (so) what would I be looking at other (girls) for?
The negated reduplicated form means ‘not doing anything’:
Di situ cewek-ceweknya nggak ngapa-ngapain.
at there girls-nya not do.anything
The girls weren’t doing anything there.
Pemerintah diem aja, nggak ngapa-ngapain.
government quiet just not do.anything
The government just kept quiet; they didn’t do anything.
Banyak orang yang enggak bisa ngapa-ngapain, enggak punya apa-apa.
many person who not can do.anything not have anything
There are lots of people who can’t do anything; who don’t have anything.
There is a related transitive verb apain ‘to do what to someone’:
Gue apain elu?
I do.what.to you
What did I do to you?
This transitive form is apparently never prenasalised. It can be negated and reduplicated, meaning ‘not do anything to (someone)’:
Dia nggak apa-apain gua sih.
he not do.anything.to me dp
He didn’t do anything to me.
It also occurs in the passive:
Kira-kira kalo dari mahasiswa sendiri, ini mengharapkannya dia diapain sih?approximately if from student self this hope-nya he have.what.done.ton dp
From the point of view of the students themselves, what do you think theyhope is done to him?
Diapain lagi sih sama dia?
have.what.done.to more dp by her
What else did she do to it (her hair)?
Diapain can occur in statements, meaning ‘have something (like that) done (tosomeone)’:
Enggak sampe elu diinjek-injek, enggak sampe elu diapain.
not until you trodden.on not until you have.what.done.to
They don’t go so far as to tread on you(r toes), not so far as to do something likethat to you.
This also can occur reduplicated after a negative to mean ‘not have anything done (tosomeone)’:
Saya kan boleh dibilang kagak bisa diapa-apain.
I dp can be.said not can have.what.done.to
You could say that I’m someone who can’t have anything done to him.
CJI Colloquial Jakartan Indonesian
dp discourse particle
FI Formal Indonesian
H High style; forms associated with FI
L Low style; forms associated with CJI
Reference: Colloquial Jakartan Indonesian (Pacific Linguistics, 581) by James Neil Sneddon (2006)