Indonesian doesn't use the form of the verb, such as go/going/went/gone, to refer the past, present or future action. Instead, auxiliaries like (sedang "continuous -ing" ; akan/mau "will"), time adverbs (besok "tomorrow") or just context are used. Observe what Mrs.Darmo, Udin (he) and Tuti (she) are doing in the market (pasar).

Bu Darmo sedang membeli pisang (Mrs.Darmo is buying banana).
Udin akan membeli baju (Udin will buy a shirt).
Tuti sudah membeli sayuran (Tuti has already bought vegetables).

Not much will go wrong with word order. It may be either subject followed by predicate or reversed. *Sentence stress and intonation must be taken care of.
The sentence "Udin akan membeli baju" or "Akan membeli baju, Udin" is common.

Bahasa Indonesia "Indonesian" uses roman script. The spelling is regular and it is not tonal.

Although verbs in Indonesian do not change according to tense, it makes changes in different way. In the example above, the verb membeli "buy" comes from the prefix me(N) and a root beli. *me(N) + beli = membeli. Suffixes "-kan" i.e. "membelikan" and "-i" are the most frequently used. Look at the following example for comparison.

Simple sentences
Ini Tono (he). Tono sekolah di sekolah negeri. Hari ini ada kelas bahasa Inggris Pak Adi. Tono senang belajar bahasa.
(Lit. This is Tono. Tono studies at a public school. Today there is an English class by Mr.Adi. Tono likes to learn language).

Sentences with suffixes
Ini Tono. Tono disekolahkan di sekolah negeri. Hari ini ada kelas kelas bahasa Inggris yang diajar Pak Adi. Tono tidak senang mempelajari bahasa. (Lit. This is Tono. Tono is sent to study at a public school. Today there is an English class taught by Mr.Adi. Tono doesn't like to study lang.).

Other examples:

root word: naik (to get on/ride a vehicle ; increase)
menaiki (to climb on) ; menaikkan (to lift, to raise)
root word: sewa (rent)
menyewa (to rent) ; menyewakan (to rent out)