American Phrase Post
In America, we may use the saying “can I

help you?” Usually this phrase is said when speaking. Though it may sound kind, it usually isn’t. Usually what we are asking is, “what do you want” it a “rude” way. Some situations we may use it are:
If someone is staring at you, you may look at them and say “can I help you?”

If someone is standing very close to you, you may turn around and say “can I help you?”

Or maybe if someone is asking you weird questions or saying odd things, you may say, “can I help you with something?”

Again, this is to show that someone is bothering you and you are basically asking what their problem is. Don’t say it to anyone in a formal situation.
Hope that this helps :))