Thanks for trying guys lol.
Fully convertible = able to be openly traded on markets. At the moment, as far as I'm aware, the PBoC keeps a the supply of Yuan very tight in order to manipulate the value and peg it to the US dollar; articificially low if you believe many economists. This makes Chinese goods much more competitive on price on world markets, pushing up their import volumes and creating demand for new plant and equipment in their home country thereby driving their economy to industrialise.
I'm of the view that this growth strategy is reaching its used by date, and so China will need to shift its focus towards building domestic markets and encouraging consumption rather than growing through business investment and exports. Floating the exchange rate (or making it fully convertible for those following at home) will speed this process up as it would reduce the prices paid for imports by Chinese wholesalers and consumers and boost their standards of living. There's alot more to add there if anyones interested.