Difficult conversations are tough by their very nature. If you want to avoid making them even harder, a post by Psychology Today suggests staying away from sentences with "but" in them.
We often use "but" to soften the blow of bad news or a critical comments. Unfortunately, when we do this, everything before the "but" is pretty much ruined. Instead, you can either remove the "but" completely or get the bad news out of the way first:
Rather than create this stress in your partner, then, consider phrasing your comments (positive and negative) in a direct manner, ending with the "good news" rather than starting with it: "I thought the meatloaf was a bit undercooked, but on the whole, I really found it to be tasty." Now that you're done dispensing the bad news, you can leave your partner with a positive bottom line.
In a truly difficult conversation, the stress of anticipating a "but" is even greater. It's one thing to be talking about meatloaf, but quite another to be discussing the future of your entire relationship. By putting your concerns out there right away, you don't leave your partner in suspense while he or she waits for the real truth to emerge.
It makes sense. Nobody likes to sit on the edge of their seat waiting for the other shoe to drop. This way, nobody has to.
5 Communication Tools You Need for Difficult Conversations [Psychology Today]