This is quite tough. I'll try nevertheless.
"Bukan" is "not" in Malay. "Tidak" is "no" in Malay. So the usage
is more or less the same.
Some examples...
English: This is not gold.
Malay: Ini bukannya emas.
English: No one in
the world is immune to AIDS.
Malay: Tidak
seorang pun di dunia dapat mengelak dari dijangkiti penyakit
AIDS.
However there are various examples where "tidak" is used to
describe things which usually meant 'Not' in English.
English: Having a degree does not necessarily means having a
decently-paid job.
Malay: Dengan mendapatkan ijazah tidak semestinya bermakna akan
mendapat jawatan yang bergaji tinggi.
