One of the great pleasures of teaching at a top global university like the University of Sydney is the opportunity to teach students from all around the world. More than one-third of Sydney's students hail from overseas, and that doesn't even include Kiwis. We're a veritable United Nations of education. As an American expat myself, I feel right at home.

It is often said that international education enriches both the visitors and the hosts — and at its best, it does. But intercultural exchange requires real communication, and unfortunately many of our international students don't speak English well enough to make Australian friends. At the University of Sydney, most of those alienated international students come from China.

It's not their fault. They've put in the hours and jumped through all the hoops. But when it comes to mastering a language, study only gets you so far. To really learn a language, you have to live it. When nearly a quarter of your fellow students come from the same country as you do, it's tempting just to fall back on your home language instead.

Roughly 24 per cent of all students at the University of Sydney come from China. The figures are nearly as high at UNSW (23 per cent) and UTS (17 per cent). There are more Chinese students at these three inner-Sydney universities than in all 33 public universities in the US state of California. This extraordinary concentration makes it all too easy for Chinese students to live in a Chinese bubble.