They are just for emphasis.
"I see leh and meh all the time, leh.
"I see leh and meh all the time, mon.
"I see leh and meh all the time, you know.
Singapore do not have a main language, like English is for
Australia.
But has four official languages. English, Chinese, Malay, and
Tamil.
We have our own pidgin English called Singlish.
"Cannot say one, meh?" <"You mean, I shouldn't mention
it?">