"That writer is my father."

Translation: Penulis itu adalah ayah saya.

[Jan320480]

Why not' penulis itu ada ayahku'

[Arkonide]

I would dearly like to know when to use 'adalah' and when leaving it out.

[octavzlatior]

My understanding is that adalah is used when you 'define' something. 'ada' is used for other meanings of 'to be', for example when you locate something.
Pisang adalah buah
Pisang ada di dapur
But I'm not really sure why sometimes you can leave them out. My understanding is that they are usually optional, maybe this is not always accurately reflected in the exercises?
I realize I wrote this just to say that basically I have no idea :))

[Jan320480]

me too!