Mandarin - native speakers about a billion
Arabic - about 300 million
English - about 400 million.
"... an estimated 18 per cent of new dwellings in Sydney and 14 per cent in Melbourne are being purchased by Chinese nationals."(http://www.abc.net.au/news/2014-03-...4-billion-dollars-in-australian-real-/5300494)
Jokes are funnier if they're accurate.
