You may be complimenting:

That is a great idea, but… [it’s really not a good idea, my way is better].

You may be concerned:

You’re doing a good job, but… [you stink! You are nowhere near good enough.]

You may be angry:

I told you to do this, but… [I wasn’t clear, but I don’t plan to admit it’s my fault].

You may be busy:

I’d love to spend time talking to you, but… [I do not consider what you have to say important].

“But” sends the message that the first half of your statement is insincere. We all say the word, “but” much more than we consciously know.

What to do?

Pause or use the word, “and”. It can make all the difference in the world. Don’t replace “but” with “however.” It softens the blow, but conveys the same harsh message.

When you pause, it also gives you an Opportunity SpaceTM to decide what you will say next, and how best to convey the message to you hope to convey.

The word “and” is inclusive, and while it provides you the opportunity to express your main point, it also allows you to acknowledge the current situation in the first half of your phrase.

You can also add small phrases to soften the delivery of your message such as “I’m wondering…” or “I may be wrong…” or “If I understand you correctly…”

For example,

“That’s a great idea, but what’s it going to cost?”

Instead, try:

“That’s a great idea, and I’m wondering what the cost will be.”

Another example,

You’re doing a good job, but your times are still way off.

Instead, try:

You’re doing a good job at [specific task], and I’m confident you can continue to improve your times.

Just for a day, track how many times you say, “but”. In a factual sentence, it may be very useful. However, in discussions with another person and about another person, it is rarely constructive. Replace “but” with a pause or “and”.