One thing that is hard is that you cannon control the impact of your words. You can influence it. With skill and perceptiveness you can strongly influence it. But you cannot 100% prevent someone from interpreting your words as an attack any more than the driver of a car can 100% guarantee he’ll never fatally collide with anyone.

Good resources for understanding how to control the impact of your words include the book Difficult Conversations and others from the Harvard Negotiation Project.