Young people everywhere like to use slang terms that their peers use. However, not all English slang terms are appropriate for all situations. In fact, some terms are insensitive and disparaging. To demonstrate that you are an educated, culturally-sensitive person, avoid using the following terms in your everyday speech:
"That's so lame!" The word "lame" originally referred to a person who was not able to walk. Although the word is not commonly used these days to refer to a person who has a mobility impairment, some who do have such a disability might be hurt or offended by this phrase. Use a more neutral phrase, such as "That's ridiculous!" to describe something that does not meet your approval or standards.
"That's dumb!" Like the word "lame," the word "dumb" used to refer to a person who could not speak. English speakers do not usually use this word anymore to refer to a person with a speech impediment, but a person with a speech impairment might be offended by this phrase. Again, use a more neutral phrase.
"That's so gay!" Unfortunately there are still many people in today's society who are unable to accept gay and lesbian people as equal members of our culture, despite the fact that medical, psychological, and sociological research indicates that sexual orientation is a natural variation of the human condition. Whatever one's opinion on this topic, it is never acceptable to disparage another group of people based on their natural characteristics.
"Cry/Scream/Throw a ball like a little girl." Using this phrase indicates that you think little girls are incapable of controlling their emotions or playing sports effectively. In fact, there are many very capable female athletes, and little boys are just as likely to cry or scream as little girls. While researchers debate the extent of the influence of biology on behavior, choose phrases that are sensitive to the feelings of people who are different from you.
"Man up" or "Grow a Pair of __." In many cases it seems like the pendulum has swung the opposite direction, and now it is common to disparage men in our language. Men can suffer from depression, anxiety, and other mental/emotional disorders as much as women, yet we often criticize a man who seems hesitant, fearful, or anxious, making him out to be effeminate or emasculated. This is terribly unfair to the man, as we have no right to judge the internal life of that individual. Instead of extending criticism, why not just ask the man, "Why are you thinking or feeling this way?" His answer will help you understand him, and it might help him work through some of his issues in a healthy way.
Put yourself in the other person's shoes: You wouldn't like it if people went around saying "That's so Korean," or "Don't be an Indonesian" or "You act like a Chinese" would you? The world would be a much better place if we would just treat others the way we would like to be treated ourselves. That's a big, big change for the world to make, but change starts with the individual.