"This is my ball."

Translation: Ini bolaku.

[TheZakken]

How is the grammar of this sentence different from the grammar of "This book is mine" I wrote "Bola ini punyaku" but it was marked incorrect. But for "This book is mine" I wrote "Buku ini punyaku" and it was accepted. are these different? Very confusing

[Rick392366]

They have the same meaning, but a different structure.
Ini bolaku = This is my ball.
Bola ini punyaku = This ball is mine.

In the first sentence, "ini" is the subject of the sentence.
In the second sentence, "bola" is the the subject of the sentence.

There is a difference in emphasis.
Something like this :

Ini bolamu ? (Is this your ball?)
Ini bolaku. (This is my ball)

Bola ini punya siapa ? (Whose ball is this?)
Bola ini punyaku. (This ball is mine)

[IlseDens]

what's wrong with: bola ini saya ?

[AVAX3M]

I've never seen such a construction so I'm inclined to believe it does not make sense grammatically. "Bola ini" by itself literally means "my ball(s)" so adding "saya" would make it mean, probably, "my this ball". But what if I'm wrong? Do you think it can mean "this ball of mine"/"these balls of mine"?

[Garry_G]

'Bola ini milikku' is not accept, bug!

[Rick392366]

Please have a look at my comment posted 9 months ago.

bola ini milikku = this ball is mine.
ini bolaku = this is my ball.

Here is more info about the word order in a noun phrase :

Adjectives, Noun Phrase, Tips & Notes, Addendum.
https://forum.duolingo.com/comment/31285942

'ini' , 'itu', Tips & Notes, Addendum.
https://forum.duolingo.com/comment/31492712

[Ants_]

ini adalah bola saya...what is wrong?

[brendanzi]

You dont need the word "adalah". I think you are trying to directly translate the word "is" with adalah. In this instance it doesn't quite fit right, though it would pass in a conversation.