“‘No’ may be the most powerful word in the language, but it’s also potentially the most destructive, which is why it’s hard to say,” says William Ury, director of the Global Negotiations Project at Harvard University, and author of “The Power of a Positive No: How to Say No and Still Get to Yes.”

Ury believes that saying no is so difficult because it surfaces the “tension between exercising your power and tending to your relationship.” In other words, you want to put your foot down and be true to your convictions. But you also don’t want to estrange yourself from friends and family members. You want everyone to like you.

That’s why many people choose avoidance (like pulling down the blinds and telling the kids not to answer the door), which gets you neither respect of your opinions or warm fuzzies from friends.

A winning solution, says this negotiation specialist, is to sandwich your “no” between two “yeses.” That way you can assert your stance without alienating allies (versus enemies, which you don’t really care about, right?).

Take my wimpy approach to my neighbor dilemma. I suspect Ury would council me to push my double jogger over to my neighbor’s house, invite myself in, and tell her something like this:

“Your friendship is valuable to me. And I care about you.” (That’s the first “yes.”) “However, given all of my demands between the kids and work and all the extras I do, I just don’t have time to run errands with you.” (That was my “no…” which I can’t picture myself saying in a thousand years. I’m way too much of a people pleaser.) “But maybe once and awhile I could go to prayer group with you.” (Another “yes.”)

The conflict expert also suggests (and this is especially important in political and business negotiations) that we focus on common interests with a second party, rather than specific positions; that we develop an alternative plan to a negotiated agreement; and that we devise a plan that is easy for people to agree with (use lots of logic).

In a culture so demanding of our time and productivity, Ury claims that it’s more important than ever to say no. Because, according to him, “to say yes to the right things, you have to say no to a lot of other things.”

That’s pretty much Commons Sense 101, but I can surely benefit from a refresher.