If you think negotiations between China and the West are a bit fraught these days, think about the challenges of state-to-state communications in the late 1700s. For starters, anyone caught trying to teach the Chinese language to foreigners risked being put to death. At the same time, all translations of official pronouncements between English and the other side's scrawled ideograms had to be mediated through a third tongue, mostly Latin, Italian or Portuguese. And even the most well-intentioned diplomatic overture required a dangerous sea journey of over a year, followed by weeks of discussion over forms of bowing and kowtowing that provoked more mistrust than understanding.
Moreover, interpreting was not really recognized as a profession at the time. The main individual entrusted with dealing with the crucial 1793 Macartney embassy, the first formal approach by the British to the court of the Qianlong Emperor, was the entirely inexperienced Li Zibiao, also known as Giacomo or Jacobus Ly, who had been born in China's remote west and educated in Italy as a Catholic priest.