The first problem is lacking feedback. Nobody would correct you, if there is a difference, until you find it by yourself too late or in a nasty way. Sometimes people's disfavor is very subtle, because they want to be polite too. You will have to sense it.

Many years ago, my cousin visited us in China. With her were her friends, a Filipino american family (I guess they were raised in the U.S.). They gave me a gift and I didn't open right away. They asked why? They didn't seem to be happy and accused me of being rude.

Another year, I visited Germany. My family has a very good German friend. She insisted to give me money and gifts as it was during the Chinese new year. But based on my culture training I refused it. She seemed to be upset, she thought our family was refusing her.

The second problem is that culture is really a habit thing. When it grows on you, it is really difficult to change. When people say "Oh, you are really good at this." The Chinese response would be "No, I'm not good at this at all!" But I would look like an idiot if I say this in the U.S. I knew it, but it really needs some mental power to correct it, because conversations happen so fast and sudden, you don't have time to think.

I spent a lot of time to change it to "Really!" and finally only recently I had learnt to respond "Thank you!"