Indonesian (Bahasa Indonesia) is the official national language of Indonesia and mutually intelligible with Bahasa Malay; in other words, the two should be considered a dialect of each other, rather than separate languages. It differs mainly in the loanwords from other cultures (e.g., English for Malay, Dutch for Indonesian).
Bahasa Indonesian is based on a version of Malay from the Riau islands in western Indonesia, today called Riau Indonesian. It was first declared the official language with the declaration of Indonesian independence in 1945, following the 1928 unifying-language declaration in the Indonesian Youth Pledge (Sumpah Pemuda).
Almost all Indonesians speak the language, although less than 20% have it as their native tongue.
Bahasa Indonesian Lesson One; Pronounciation, Consonants, Vowels and Dipthongs, Numbers, Times
Bahasa Indonesian Lesson Two; Greetings and Responses, Forms of Address and Pronouns, Statements
Bahasa Indonesian Lesson Three; Prepositions, Interrogatives, Requests
Bahasa Indonesian Lesson Four; Body Language and Conversation, Example Small Talk, Additional Family and Occupation Terms
Bahasa Indonesian Lesson Five; Immigration, Directions, Transport, Directions