"Why" questions and why to avoid them
Don’t ask questions that start with “Why” unless you want your counterpart to defend a goal that serves you. “Why” is always an accusation, in any language.
The advice of avoiding “why questions” is from the book “Never Split The Difference” by Chris Voss. If we think about it, how straight to the point is that? When was the last time someone asked you “Why this” or “Why that” and you weren’t left with a bit of sour feeling. For example, many bosses would use “why questions” in meetings after something had gone wrong (“Why did you do that”, “Why didn’t we sell enough”, “Why couldn’t we release on time”, etc.). However, that might be counterproductive in many cases.
The better alternative is asking calibrated and open-ended questions that direct the other person towards solving your problem. Such could be “How” or “What” - “How can we solve this problem?”, “What can we do to improve the process?”, etc. Coming up with these non-why questions will lead to better results for both parties in most cases. Moreover, they may start flowing naturally to you once you remember to avoid “why questions” in negotiations as a rule of thumb.