Prefix “di_” in Bahasa Indonesia

After discussing prefix “me_” and its derivatives including prefix “mem_”, “men_”, “meng_”, in this post I would like to address prefix “di_” which is usually used to make passive verb.

Note: Don’t be confused with preposition “di”. This one is prefix “di-“ which should be written in one word with the root word.

Root Active Passive
Makan Memakan - eat Dimakan - to be eaten
Baca Membaca - read Dibaca - to be read
Tulis Menulis - write Ditulis - to be written

For some words, adding prefix “di-“ to change active verb into passive verb should be followed by suffix “-i”. Unfortunately, there is no any explanation you can find in any Indonesian grammar book about this point.