Positive language is a great way to avoid accidental conflicts sprung from miscommunication. While the change is subtle, the effects are drastic.
Say one of your products is backordered for a month and you need to relay this information to a customer immediately. Consider the following responses:
Negative language: "I can't get you that product until next month. It is back-ordered and unavailable at this time."
Positive language: "That product will be available next month. I can place the order for you right now and make sure that it is sent to you as soon as it reaches our warehouse!"
Redirecting the conversation from negative to positive places focus on the proposed solution. When the outcome takes center stage, it reduces the odds that customers will be upset.