The picture above is the list of Grammar (Tata Bahasa) lessons I am learning in the mornings right now from Unit 3. You can see all the different prefixes and suffixes you can add to each base word (kata dasar). Each of these additions, changes or adds something to the meaning of the word and has rules attached to it, like some need to be followed by a preposition. Here are a few examples:
Lesson #41: Ber + Adik (younger sibling) = have a younger sister. Or in my case I could write "Saya beradik tiga" (I have three younger siblings). There is a more formal and longer way of saying it too of course - Saya mempunyai tiga adik.
Lesson #42: Ber + Topi (hat) = wearing a hat. Dia bertopi hitam (He is wearing a black hat).
You can add "ber" and "ter" to a whole lot of root words to make someone have something, wear something, something to exist, be a multiple of a number, happen unintentionally, or be the most, just to name a few. There are lots of different combinations of prefixes and suffixes you can add to make words say something new like me+root word+kan or me+root word+i.
Then they get a bit more complicated. To start with you can add the prefix "me-" to most of the nouns to make a verb. But you can't just add it to all of the words in the same way, it all depends on what letter the word starts with. For example if the word starts with "l" like the word lihat (look) you can just add me+lihat = melihat (to look). If however it starts with a "b" like beli (buy) you have to add mem+beli = membeli (to buy). To different starting letters you have to add, mem, men, and meng, so you just have to know which one goes with which and memorize each one. Then it gets even a bit more difficult with some words, like those that start with p, t, k, and s. When you add the prefix "me-" to words that start with those letters you have to throw those letters out and replace them with either, m, n, ng, or ny. For example: the word "kering" means dry but the word "mengeringkan" (the k turned into a ng) means to make something dry. Yep, more memorizing!
Where it gets really interesting though is when the adding of all these prefixes and suffixes actually changes the meaning of the word. For example "umum" means general or public but the word "mengumumkan" means to announce something.
Well there you have it, just a little glimpse into the fun of learning Bahasa Indonesia. There is a lot of new information coming at me every day and it quickly gets overwhelming. As of today I am halfway through my second unit (of six) of Language School!