Questions & Answers about Buku ini milik saya.
- buku = book (noun)
- ini = this (demonstrative, like this in this book)
- milik = ownership / property / belonging (a noun meaning possession)
- saya = I / me (first-person singular pronoun, polite/neutral)
So the structure is literally: book – this – possession – I, i.e. This book is (the) possession of me.
Indonesian normally omits a verb like “to be” (is/are/am) when linking a subject to a noun or adjective.
So instead of saying Buku ini adalah milik saya, people usually just say Buku ini milik saya.
Adding adalah is possible and sounds more formal or written: Buku ini adalah milik saya = This book is mine (formal style).