As a world nation these would be the percentages of who speaks what as a first language:
13.69%Â Â Â Mandarin Chinese
5.05%Â Â Â Spanish
4.84%Â Â Â English
2.82%Â Â Â Hindi
2.77%Â Â Â Portuguese
2.68% Â Â Â Bengali
2.27% Â Â Â Russian
1.99% Â Â Â Japanese
1.49% Â Â Â Standard German
1.21% Â Â Â Wu Chinese
So surprisingly when you think English is the world's choice for a first language you would be wrong.
Brushing up on even the basics of a language will always benefit you and show you in a good light when dealing cross cultural relations, even if the one your communicating with speaks English as a second language it shows effort and respect on your behalf even knowing a few words or sentences of their language.
China is the awakening economic and commercial giant in the east and businesses are finding that they are doing more and more business with the Asian sector, so as China has a strong culture and heritage it also has an exact way of doing things on a business and also a personal etiquette level, even learning the basics of Mandarin Chinese would and a little research into customs could reap you large rewards.