How do you disagree with or complain(抱怨)to someone in a polite way?
Your teacher says Pluto(冥王星)is a planet and you know that it's not. Here's one polite way of telling the teacher. You can say, "Excuse me, teacher, but I have heard that scientists now don't call Pluto a planet." If you say "excuse me" and don't use words like "wrong", your teacher won't feel unhappy.
And there are times when we need to complain. You have bought an MP3 player. The shop assistant tells you that the player also has a radio. You buy it but find that it doesn't. You need to go back to the store and complain. You can say to the assistant, "I was told that the MP3 has a radio but it doesn't have one. I would like my money back please." This is a polite way of complaining.
We havedisagreementwith friends sometimes. If your friend leaves tea cups and candy paper bags here and there, you can say, "It's really a bit difficult to do my homework here. It is a little dirty. Would you mind being a little tidier, please?"
But remember, if you have to disagree with someone, it's always best to be polite!
