Some people say that bahasa Indonesia is a bit easy to learn than other languages. If it is compared to English, bahasa Indonesia has no verb tense. Besides, it has lesser vocabulary than English. However, this language is not that easy to learn. Remember that learning the language means learning the culture where the language is mainly spoken. However, if there is a will, there is a way - meaning that, it is still possible to be learned even if you do not say in Indonesia.
In general, language learning needs consistency. Language learners need a lot of input that support the learners to able to produce expressions in target language. Besides, resources are also needed - both written and spoken.
Video embedded from Youtube below is provided by TEDx Talks entitled "How to learn any language easily" presented by Matthew Youlden.
#1 Online Language Exchange
Indonesians are famous for their friendliness. It is easy to find Indonesians who can teach you bahasa Indonesia. In this digital era, you can find them on social media such as Facebook or Twitter. Skype is also good for learning bahasa Indonesia. There are many Indonesians that you can find on Skype. To have them as your teacher of bahasa Indonesia, simply state your intention and ask them that you will teach them English if they want to teach you bahasa Indonesia. To find them over the Internet, investigate websites and forums that offer English lesson.
Newspaper enables you to learn bahasa Indonesia too. The language used on newspaper ranges from less to formal. Go find your online newspaper to learn bahasa Indonesia. This trick is for those who have basic knowledge of bahasa Indonesia. If you want to acquire more vocabulary and grammatical structure that is common, reading newspaper is a wise option.
#3 Academic Journal
If you want to meet more formal grammatical structure as well as vocabulary, go find academic journal written in bahasa Indonesia. This is helpful since journals are peer-reviewed before they are published. So that, manuscripts that contain non-formal and less-formal grammatical structure and vocabulary will be excluded from publication. If you are interested in this option, try to find journals indexed by Scopus.
#4 Travel to Indonesia
Indonesia is one of the most favored places to visit by foreigners. Indonesia is famous for its natural beauty and its friendliness. Indonesia has Bali, Lombok, Papua, and Toraja. If you visit these spots, you can easily find Indonesians that are ready to serve you to learn bahasa Indonesia. Many Indonesians will teach you bahasa Indonesia for free.
#5 TV and Podcast
Nowadays, there are many TV stations that enable you to access their contents online. News are all presented by using formal sentences. If you want to learn the less-formal, try to find entertainment programs. Besides, podcast presented by native speaker of bahasa Indonesia is also available over the internet.
(Read also: Podcast Bahasa Indonesia: Formal or Less Formal?)
If you want more detailed 'how to' in learning bahasa Indonesia, I provide a blogpost entitled "How to learn bahasa Indonesia" that talks about technical points to be considered.