Grammars
There are numerous grammars on the market and all have their advantages and disadvantages. The Indonesian Reference Grammar by James Neil Sneddon is one of the most comprehensive grammars and we highly recommend it. Sneddon also published Understanding Indonesian Grammar. This a reference and workbook designed primarily for intermediate and advanced students in senior years of high school and at the university level. It is very useful for learners as it contains exercises that you will not find in the Reference Grammar.
Do I need a Grammar?
Users of «The Indonesian Way» do not need to acquire a grammar (although we still recommend it). We highly recommend that as students progress to more advanced courses like «Aneka Baca», «Baca Yuk», «Serba-Serbi Nusantara», «Ada Apa dengan Cinta», or «Anak Jalanan», they acquire and regularly refer to Sneddon’s Reference Grammar.
Dictionaries
Bilingual Dictionaries
A bilingual dictionary or translation dictionary is a specialised dictionary used to translate words or phrases from one language to another. Most bilingual dictionaries are bidirectional. You will use the Indonesian–English version more often than the English-Indonesian version, but it is a good idea to purchase both.
The most superior Indonesian-English dictionary available is A Comprehensive Indonesian-English Dictionary: 2nd Edition by Alan M. Stevens & A. Schmidgall-Tellings (Editors). However, it comes with a relatively high cost. An economical yet reliable alternative is Kamus Indonesia-Inggris: An Indonesian-English Dictionary by Hassan Shadily along with an English-Indonesian dictionary by the same author, both of which are commendable. They are slightly outdated, but when you can get a cheap second-hand copy, go for it.
Another excellent option is the English-Indonesian Learner’s Dictionary of Today’s Indonesian by George Quinn. These are the only recommendations we have at the moment. If you are in Indonesia, book shops sell Indonesian-English dictionaries for a few bucks. Stay away from them!
Keep in mind that excellent bilingual dictionaries are also available for other languages than English.
Monolingual Dictionaries
If you already have a relatively high proficiency in Indonesian, consider a monolingual dictionary instead. The Kamus Besar Bahasa Indonesia, commonly abbreviated as KBBI is the official Indonesian dictionary. The official Malaysian dictionary is called Kamus Dewan and you can perfectly use it for Bahasa Indonesia as well. We do not recommend monolingual dictionaries for beginners, but it becomes an excellent resource as you progress.
Finding a paper version of the KBBI outside of Indonesia is a challenge, but you don’t need one anyway. The KBBI is available online for free, and it is even better than the print version as it is constantly updated. You can access it KBBI website. It is also available as a free application for iPhones and Android smart phones.
Online Dictionaries
Online dictionaries are great. With a print dictionary, you have to look up the root word. You will not find the word perusahaan under the letter p because the root word is usaha. Online dictionaries make it easy, but you need to be aware that even the best online dictionaries are inferior to printed dictionaries. Until now there is not a single online dictionary that is fully reliable. The only online dictionary that we can recommend with caution (it contains a few mistakes) is Indodic (free). We also strongly advise against using Google Translate. You can use Google Translate (with caution) to translate entire sentences, but for translating single words it is pretty useless as it only provides one translation
How can I look up the origin (etymology) of an Indonesian word online? What dictionary gives word origins?
There is the Kamus etimologi bahasa Melayu by Chong, Mun Wah, which should be easily available. Or Google for kamus etimologi bahasa Indonesia but they are all published in Indonesia as paper copies.