By not implying that you should add a question mark "?" to complete your sentence.

People have different ideas of rudeness...often incompatible with each other. For example: as a child I learned that it was rude to visit someone at their home without being invited first. The only exception was some sort of emergency (e.g. car broken down on a country road), and in such a case of course you apologized profusely for intruding on someone's property and knocking on their door uninvited. Now compare that to one of my best friends, a Jehovah's Witness, who was incensed that I considered such behavior rude. He was insistent that it was not rude...but where and when I grew up, it most definitely was, and of course I still consider it so. *** Or, take another example. As a child we were taught in school and by our parents that it was rude to refer to a woman as "Miss" unless we knew for certain that she was unmarried. At that time and place, a married woman received greater respect than did an unmarried woman. (Being married was a sort of sign of maturity, just as it was for a man, but a man's title does not indicate such.) The place I live in now, "Miss" is not only common to apply to married women, it's often preferred by them. (Seems completely backwards to me!)

If others see you as being rude, it's time for you to reflect on your own personality. There will always be times when people will take you the wrong way, but if it happens frequently, then the problem is on your end.

be well mannered and smile