How do you set boundaries with a coworker who keeps walking in to your office with a question, when you are just busy working?
Usually my other coworkers approach and make some noise and signal their arrival in some way, and wait till I acknowledge them or if I don't, they say something and wait until I do.
But this one person walks into my office walks right up to me and starts speaking their question. That would be okay by me if I was waiting for them already, but I'm not! Or if they were to continue a recently-started discussion, that would be okay too, but they're not! It's a new unexpected one.
Thankfully that does not happen often, but when it does, I find it unsettling.
How do I handle this?
Other than putting up with it, I can think of saying something like: "When you come to me with a question, I prefer you wait till I acknowledge you first, or better yet, send me an email". But that risks sounding brash. I want to avoid negativity but nevertheless have some tools to assert my at-work boundaries, and even if there is a conflict, make it one that is least likely to cause me issues later on.