It's no joke. I thought everyone here spoke English but in fact it is a combo of English and Singlish. I find that employees at all the official companies - banks, utility companies, cable company, they all use Singlish and it is difficult to understand.
I most commonly here: Can, lah. or Can lah? or Cannot. or Can Can.
Lah softens a sentence as if to add Y'know at the end of it.