IPA ŋaʔgolʊŋ

Remember the glottal stop is not part of the main verb; it is a prefix that marks an immediacy. You should practice saying the word with and without the glottal stop.

ŋaʔgolʊŋ / ŋagolʊŋ

The audio file has the glottal stop.
http://words.bininjgunwok.org.au/words

nga- first person singular (W)
(ng)a- is the Kundjeyhmi form, i.e. the initial nasal sound is optional. In Kunwinjku it must be pronounced.
-h- immediacy marker (if needed)
-kolung is the verb.

Here are the forms of the verb:

-kolung 'non-past' (i.e. present and future)
-koluy 'past perfective'
-kolungi 'past imperfective' (used to go down, were going down in a continuous sense)
-koluyi 'irrealis' (negative or should/might have)
-kolu 'imperative'

The reflexive/reciprocal form -kolurren can be used to indicate plural subjects. Here's an example in Kundjeyhmi:

Nabene mayh a-nang kam-kolurren kaddumbe djohboi arri-ngeybun mimkoy.
I saw those birds coming down (to the billabong) from higher ground. Dear little things, we call them mimkoy (red-eyed partridge pigeon).

You could say this to a child up in a tree:

Yim-kolu warde yi-mankan!
Come down here, you might fall!

Or if you're a passenger in a car:

Ma, kondanj nga-kolung.
OK, I'll get off here.