How to use 'bila' and 'apabila' correctly

When the Malays speak among themselves they use 'bila' to mean 'when' as a question and as a conjunction. I also speak this way.

However, in written Malay, 'bila' is used strictly for asking questions. For example, if you want to ask when the monthly test will be held, then you say, "Bilakah ujian bulanan akan diadakan?"

On the other hand, if you mean "when I see him I will tell him the new date for the meeting.' you must write, "Apabila saya berjumpa dengannya, saya akan memberitahunya tarikh baharu untuk mesyuarat itu."

Hence 'bila' is used when we want to know the time, day, date and year of a certain event while 'apabila' is used as a conjunction in sentences. Here are further examples of sentences involving 'bila' and 'apabila'.

1 Bilakah kamu akan bersara? [When are you going to retire?]

2 Bilakah pasar raya baru itu akan dibuka? [When will the new supermarket be opened?]

3 Hari lahir saudara bila? [When is your birtday?]

(Note that the particle 'kah' is used when Bila is used in front of a sentence. If it is used at the end of a question no particle is needed.]

4 Apabila saya pergi ke bandar, saya pasti mengunjungi kedai buku. [When I go to town, I will surely visit a book shop.]

5 Apabila hujan, penjaja itu tidak dapat berniaga. [When it rains, the hawkers cannot do their business.]

6 Apabila saya besar nanti, saya ingin menjadi doktor. [When I grow up, I want to be a doctor.]