The English language is one of the most expressive languages on the planet. For this reason, there are multiple ways of saying the same thing. However, sometimes just changing one word in a sentence or phrase can slightly alter its meaning. One example is the term “sorry to bother you” as opposed to the term “sorry for bothering you.”
Both terms are very similar and convey the idea that you want to apologize for interrupting or for inconveniencing another individual. However, these terms are different.
“Sorry for bothering you” refers to an action that took place in the past. For example, you ask a favor from a friend. In doing so, you made them stop what they were doing. So after interrupting them, saying “Sorry for bothering you” is the right way to respond for the interruption that took place.
“Sorry to bother you” on the other hand is something that you would say before interrupting a person or as a way of introducing the interruption. For example, you may knock on a neighbor’s door looking for a cup of sugar. When they come to the door, the first thing you say to them is “Sorry to bother you” and then you proceed with your request for a favor. This term is essentially putting your listener on notice to the fact that you are going to ask something of them.
Either way, saying sorry for bothering you or sorry to bother you is a polite way to acknowledge that you are interrupting someone’s activities.