Is "Ketika" Past Tense?

by Raashid Kola
(Coventry, UK)

Hi Wan

I had subscribed to your mailing list quite some time ago, and thoroughly enjoy your exposition of BM.

I have a question with which I hope you can assist?

I want to say "My first exposure to BM was when I was 15". The word I am in pursuit of is "exposure". I know terbongkar means to "expose" but that's the word I am not looking for.

Also I want to find the past tense for "when" as "when I was 15". I understand in Bahasa Indonesia they use the word "ketika" for past tense and "kapan" for present and future tenses.

I really appreciate your help.

Terima kasih banyak.

R. Kola

Coventry, UK.