There are certain things which are considered bad manners in Western countries to talk about in public. It is very important to know these and avoid them. The subjects to be avoided are: body functions, or anything connected with the more private parts of the body, details of birth, details of unpleasant illnesses; income or salary of friends, or prices of their possessions; the age of the person one is talking with; personal questions or remarks, such as “why don’t you get married?” or “I should think you would want to have some children.” Some of these are allowed in Chinese society, but they are all taboo in formal Western society.
It is not good manners to speak of one’s own country as if it were more important or better than others. But neither is it good to speak badly of one’s country or call it “unworthy”.
Western manners do not require one to say anything that is untrue, but it is best to avoid being too frank about things which would make people feel uneasy--- unless by doing so you feel some good might come of it. Speak naturally but not boastfully of the good things in your own country, and speak appreciatively of what you can approve of in the foreign country.
It is considered impolite, when in a small group, for two people to talk together in a language unfamiliar to the others. If for any reason you find it absolutely necessary to do so, you may say to the others, “Would you pardon me, please, if I explain something to Mr. Spooner in Chinese?”
In a conversation or discussion it is bad manners to take more than your share of the time in talking when others wish to talk also. It is bad manners to interrupt anyone else when he is talking. It is bad manners to be dogmatic and sure of your own point of view, suggesting by your speech or action that no one else’s viewpoint is of any value. It is bad manners to get cross or angry in a conversation or discussion. If you think as much of others as of yourself, you will not make any of these mistakes.