Probably he picked up a smattering of it from his colleagues'
conversations.
Anyway, I don't speak Mandarin, and I'm not expected to speak
Mandarin.
I don't expect PRC salespeople to recite Shakespeare's sonnets
or read from Coleridge, though I would be delighted if they
could.
But I would also expect an electronic components shop assistant
to know what a resistor is, and a KFC counter staff to know what is
'one Pepsi, one Pepsi Light'......
Actually I try to be an ass and refuse to speak to them in
Mandarin
Heck, if they are in Singapore they jolly well learn how to
speak English