Don’t call teachers casually

The safest way for schools to address teachers is to use “professor”. If you know the teacher's last name, you can also call him Professor XX, but do not call the teacher Sir, especially to female teachers, because they may care. Also don't call the teacher by his or her first name unless the teacher tells the student that it's okay to do so.

Don’t make marks in books casually

Studying in the United States has a lot of assignments, almost in every class. Some teachers may tell you from the beginning that every assignment this semester will be done. The progress and assignments of the class may be discussed only during class. If you know which textbooks you want to use when you choose a course, you can go to the bookstore to buy them first, but keep the receipt and ask the clerk if you can return the books, because the teacher may change the textbooks after class, and if the students feel after the class that they are too easy, too difficult, or If it is too boring, you may withdraw from the selection. At this time, you need to return the book. Used books cannot be returned, so do not write names, underline, or make any marks on the book at the beginning.

Don’t call black people “Negro”

Negro means “black people” in English (forum). It especially refers to black people who were trafficked from Africa to the United States as slaves; so never call black people "Negro" in the United States. This is true when talking to white people, and even more so when talking to black people. Otherwise, the black man will feel contempt for him; when talking about black people, it is best to use the word "Black", and black people will accept this title calmly.

Same-sex cannot dance together

Same-sex cannot dance together. This is one of the recognized social etiquette in the United States. If people of the same sex dance together, others will definitely look at them reproachfully or think that they are gay. Therefore, even if you cannot find a partner of the opposite sex, you must not dance with someone of the same sex.

Don’t take off your shoes in front of others

In the United States, if you take off your shoes or go barefoot in front of others, you will be regarded as a barbarian who does not know etiquette. Shoes can only be taken off in the bedroom, or between men and women who are passionately in love. If a woman takes off her shoes in front of a man, it means "you can do whatever you want." If a man takes off his shoes, he will be regarded as a jungle man. Barefoot natives are equally despised. It is impolite for both men and women to pull down their socks or garters in front of others; if your shoelaces are loose, you should go to a place where no one is around to tie them.