I would like to know how to ask someone about something without accusing them.
If I want to know if someone at work has used my computer, can I ask "Have you used my computer?", without insulting them?
I know that if I were to say: "Have you been using my computer?" it sounds like I think the person has indeed used my computer and I am not happy about it, but that is not what I mean.
I tend to ask very generally about the issue when I find myself in such situations.
ie. instead of "Have you used my computer?", I would say:
It looks like my computer got moved since I last used it, you haven't noticed anything have you?
In this way my question is limited to the thing you noticed that made you suspect someone used your computer, I've used this sort of phrasing many times and have never had the other person appear offended, sometimes I've even ended up with a useful clue I never thought to suspect.
Even in the cases where I still suspect the other person despite the question, asking this way makes them aware that you've noticed and had concerns about your computer which can help deter them from continuing.
This is something I used to run into with my college roommates. It's all too easy to go from "Is this your bowl in the sink?" to "Yea, but you leave your clothes in the washer for days, so who cares?" to a downward spiral with no end.
In my years living with messy people, my chief advice here would be to ask yourself:
Certainly it's not just to accuse your coworker of using your computer and then be upset with them. More likely, you're probably asking so that you can lay down a boundary and let them know that you don't want them doing something like that in the future.
So instead of trying to figure out whether or not they're in the wrong (which will sound accusing no matter how you do it--you're trying to accuse them after all!), approach this by trying to solve the deeper issue. Regardless of whether or not they used your computer, that's a boundary that you want to exert.
I may say something like:
Hey Fred! I know different people have different feelings about their computers and that I often leave mine lying around. I just wanted to let you know though that it makes me uncomfortable when other people use it without asking me. If you see anyone using my computer when I'm not around, could you let them know? Thanks!
This does a couple things--it let's them know how you feel about your computer and what your boundary is. And it also avoids accusing them by recruiting them to help enforce it. In fact, you're even putting them in a position of trust here--quite the opposite of an accusation!
I usually find what works is phrasing it a bit like "I don't mind, but just wondering if you were using my computer?" - You could add in a bit about why you need to know or if you are just curious, add "just curious..."
