If an argument were a tennis match, many of us would tear right through the net during a frenzy of back-and-forth spatting.

That’s a situation hundreds of Stanford students learned to avoid in one of the business school’s most popular electives for decades. Now the masterminds behind the course, David Bradford and Carole Robin, want everyone — not just those who can afford Stanford — to know the secret to staying on “your side of the net” during an argument.

The solution, which Bradford devised in 1969, is one simple sentence: “When you do [insert action], I feel [insert feeling].”

An argument has three pillars, which Bradford and Robin describe as “realities”:

• Your intention and motivation, which only you can see
• Your behavior, which everyone can see
• The effect of your behavior, which only the other person can see

If you make a comment that implies you know what someone else’s motives or intentions are, you’re over the net. “We think we know, but it’s really a guess,” says Bradford, a psychology expert who focuses on business leadership at Stanford.

Bradford and Robin explained this thinking, and other tactics from their interpersonal dynamics class, nicknamed “touchy-feely” by students, in their book, “Connect.” Robin, who no longer lectures at Stanford, incorporates these lessons into a program for Silicon Valley executives called Leaders in Tech.

Crossing the net sparks defensiveness and leaves you vulnerable to endless rebuttals. You can say, “You just want to show how smart you are,” and the other person can say, “No, I don’t,” and then you’re stuck, Bradford explains. But addressing your own point of view — how you feel — is indisputable. The other can’t say, “No, you don’t,” because they can’t say how you feel.

That’s where the sentence comes in. It can be hard to grasp at first. Sometimes, people slip into “I feel” without actually including an emotion.

“When I show up late repeatedly to meetings and you’re feeling annoyed, the tendency for most people is to say, ‘I feel that you don’t care.’ Well, there is not a single feeling word in there,” Robin says. “Then what you’ve done is you’re over the net. Unless I say I don’t care, then you’re making up a story based on my behavior.”

For those still struggling to stay on their side of the net, Robin says you need to eliminate two words.

“It is grammatically impossible to express a feeling in English followed by the word that or like. I feel that angry? I feel that disappointed? I feel like happy? No, it’s grammatically impossible,” Robin says. “Drop the ‘like’ and the ‘that.’ Get disciplined about ‘I feel [insert feeling word].’”

Messing up is inevitable. Trying to figure out others’ motivations is a way for people to get a sense of control in a confusing world, Bradford says. Even he doesn’t follow his own advice perfectly, but an apology can go a long way. He recommends accepting that you’ll mess up sometimes and teaching yourself to recognize when you do.

“I can say, ‘I’m sorry I said that. What was really going on for me is I was feeling ignored and put down,’” Bradford says. “We don’t have to do it perfectly. We can correct ourselves.”

Robin often hears from alumni about how they used the sentence to preserve a relationship, whether it be with a partner, friend or colleague. Years after taking the class, a former skeptical student turned big-time Silicon Valley engineer emailed her about how the sentence helped his staff. During a disengaged meeting, he instructed everyone to go around and use the sentence. When some said, “I feel like we’re wasting our time,” he advised them to use feeling words. By the end, the energy shifted as people unpacked how they felt so he could address the underlying issues.

One of the biggest relationship challenges is that people don’t tell each other the truth about their feelings and the impact of someone else’s behavior, Robin says.

“They’re not willing to be vulnerable enough to say, ‘This really matters to me’ or ‘I’m scared or hurt.’ And so they don’t build the kind of trust that’s built if you’re willing to say more to each other,” Robin says. “The main hallmarks of building strong relationships, it starts with disclosure. You have to be willing and allow yourself to be known by the other person.” That applies to people on both sides of the net.

“One of the things we really stress in the course is all of this is a choice. So when people say, ‘Well, I can’t,’ we say, ‘No, you choose not to,’” Bradford says. “We want people to take responsibility for their behavior. And that, I think, is really important because so often we don’t take responsibility for our actions.”