If you are walking the streets of London or sipping coffee at a sidewalk cafe somewhere in Paris, and you hear in plain English, "So expensive-lah" or "So hot-lah", just turn around in the direction of the voice and I guarantee you that ten out of ten, the person who just dotted his or her sentence with a lah is Malaysian.
If you are feeling homesick in a foreign land and suddenly you overhear a conversation full of Yes-lahs and No-lahs, your homesickness can be assuaged for it sounds just like home and the speakers can only be Malaysians (or Singaporians, which is close enough when you're homesick!).
Just where did this lah come from and how did it creep into the English spoken by Malaysians? It is inevitable that Malaysians, living in a multi-lingual, multi-cultural setting will inter-borrow phrases and expressions from one language to another. Thus the very unique lah, used only in this part of the world (Malaysia and Singapore), could have originated from Malay, or any of the local dialects or languages.
Only a Malaysian born and bred in this country will know how to use the lah. A Malaysian who has been away for a while can slip back into using it quite comfortably but a Malaysian who has been away for a long time, say, seven to ten years, with little contact with fellow Malaysians, may find great difficulty as to exactly when to pepper his speech with lah. Just going lah, lah, lah every first or third word doesn't quite qualify. Malaysians will be able to sniff you out in a second and tell that somehow, sorry-lah, you just don't make the grade. For example, try saying the following sentence aloud:
"I-lah tell you-lah how-lah many times-lah but-lah you never-lah...