I think you must have been wanting to answer a different post, that said something completely different from mine. I never suggested that people just visiting China should learn the language. I thought I made it abundantly clear with references to a continued stay in the country and the advantages of being able to negotiate your own contract.

When we talk to a future Chinese boss we often do not delve too much if we know his English is limited- and even if he does understand, he will often play dumb and pretend he doesn't understand you too well, to force you to forget about what you wanted to find out in the first place. If you know his language he will not be able to thwart you in such a fashion.

If this is not one of the countries you are just visiting there are many other reasons you should know how to speak Mandarin- negotiating the tenancy of a flat maybe. You may have opted for a job where your new employer sends his girls out with you to negotiate with the landlord on your behalf. Such a scenario will more often than not result in you being held responsible for all the ancient fixtures and fitting which invariably break down shortly after you have moved in. These girls who you think to be on your side will spend hours appearing to be getting the best deal for you. You will not understand a word of what they are droning on about. The school, your new school, often has a relationship with your new landlord-enough said?

Also, the icing on the cake is that you get more Chinese girlfriends.