Whether you’ve exchanged BFF necklaces or not, you may have one friend you consider your “best friend.” But, especially as you get older and go through a range of life experiences, your relationships shift and you can get closer to different people. So how can you tell if someone is your best friend? HelloGiggles spoke with two experts on friendship to get all the details about what makes a BFF. Because even if no one is asking who your BFF is anymore, you want to confirm that your friendship is true.

Film and TV have given us some great recent examples of BFFs, like the women of Bridesmaids and Broad City. But even if those characters remind you of your best friend, your relationship is special and unique to the two of you. So finding out what makes a best friend the best is less about specific experiences you’ve had with them and more about how you feel about that friendship.

That’s where the experts come in. HG spoke with licensed clinical psychologist Dr. Andrea Bonior and friendship expert Shasta Nelson about what makes a best friend. Bonior is the author of The Friendship Fix and runs The Washington Post‘s mental health advice column “Baggage Check.” Nelson created the website GirlFriendCircles.com and wrote the books Friendships Don’t Just Happen! and Frientimacy.

Both experts shared that it’s more than normal to have different best friends throughout your life. And Nelson even thinks you can have more than one best friend at the same time, telling HG, “I would say ‘best’ is a quality of the relationship, not a quantity of relationship.” But if you’re looking for signs to help you identify your current bestie—or besties—here are 22 ways to know your friend is your best friend.

“A best friend should be somebody that there’s not that fear of betrayal [with],” Bonior said. And that trust can range from your best friend keeping your secrets to always showing up for a lunch date. “There’s not that nervousness that if you reveal something that it’s going to be spread around to others. If you said you were going to meet up somewhere, there’s not that uncertainty of whether or not that person is going to show,” Bonior said.

Bonior also pointed out that trust in friendship needs to go both ways. Your best friend needs to trust you just as much as you trust them. Otherwise, you’re not really their best friend, are you?

Nelson said she evaluates the health of a friendship in three ways: Consistent interaction, vulnerable sharing, and positive feelings. When it comes to “consistent interaction,” you might think that means you can’t be best friends with people you don’t see all the time. But if your BFF lives in a different state or even a different country, don’t fret.

“I have some friends where consistency means we only talk on the phone every three months or we only see each other once a year. But there still has to be that sense of consistency. We both have to believe that the other person is still in our life. Consistency means we’re expecting to pick that back up again,” Nelson said.

With a newer best friendship, Nelson said you will need to put more time in since it’s not built-in. “If we’re building relationships, the research is showing we have to put in almost 180 hours before we feel close to somebody. That’s why we feel closer to people who we met in college or who we worked with because those hours got logged in pretty fast for us. And so consistency, when we’re building a friendship, is really, really crucial,” Nelson said.

Whether you’ve been best friends since elementary school or your best friend entered your life in the last couple of years, you want your hangout schedule to be true to you two. “For us to feel safe and feel like we can rely on that person, we still have to have some pattern that feels comfortable and familiar to our relationship where we believe we could reach out to that person,” Nelson said.

Nelson’s idea of “consistent interaction” is more than just frequent interactions over the course of your relationship. “It also includes being able to communicate in a variety of different ways,” Nelson said. “Our friendships go deeper when we’re not just interacting only on Facebook or only in person. Anything that increases the way we do consistent interaction is a way to measure the depth of a relationship.” So if you always feel free to text your friend or give them a call out of the blue, they could be your best friend.

Both Nelson and Bonior brought up the importance of vulnerability in the best friendship. Nelson noted that “the more we know about each other, the more we feel safe having shown ourselves, the more things we’ve gone through together, the more we’ve seen each other in different ways,” the closer we are.

“If we’re looking for the people who are going to be our ‘best’ friend, then we would be looking for people who we are sharing many different sides of ourselves with and practicing sharing vulnerable feelings, ideas, and thoughts with them.”

Bonior added, “There’s got to be a level of vulnerability with each other—being willing to open yourself up to that person and know that they’ve got your back. That’s got to be paramount. You reveal parts of yourself to them that you might not reveal to other people—and they love you anyway.”

Because you’re open and vulnerable with your BFF, they may know you on a deeper level. “They understand you in a way that your other friends might not,” Bonior said.

That’s especially important in the age of social media, where people may only share the positive things going on in their lives. “They really do get you. It’s not just superficial, not just pretending who you are on social media. It’s you even at your worst,” Bonior said.

Nelson defines close friendship—or “Fintimacy”—as “any relationship between two people where they both feel seen in a safe, satisfying way.” Similar to how a best friend truly gets you, Nelson noted that she believes “being seen” is of utmost importance. “Most of us just want friends who see us and affirm us and believe in us and if we could do that for each other, we will probably be able to survive almost anything,” she said.

Motivation comes in many forms, and your best friend should really be inspiring you to be your best self. “A best friend should be somebody who makes you want to be a better person,” Bonior said. “They make you feel inspired and you inspire each other to do better. Maybe they’re living their lives in such a way that you get motivation. So that means that you genuinely admire this person and they admire you. And that even though you show each other the most embarrassing parts of yourself, overall, there’s respect there.”

Imagine something has happened to you at work—maybe you got a raise or maybe you had a disagreement with your boss. In the words of the Ghostbusters: Who are you gonna call? According to Bonior, the answer is your bestie.

“Your best friend should be somebody that when something happens to you—good or bad—you want to call them right away. They come first on that list. You want their opinion on things and you want their understanding of things,” Bonior said. So while your parents, siblings, or significant other may be high on that list too, your BFF is at the top with them. And even if it’s not a phone call per se, you’ll be sharing your news with them one way or another.

Bonior noted that your best friend is someone you share all your news with, whereas other friends may only be there for you at specific times. “We all have a friend that can commiserate with the best of them. But when you have good news, they’re not that happy for you because they’d rather be commiserating.

Or the person who’s happy to cheer you on and have conversations about positive things, but doesn’t want to hear it when you might be struggling,” she said. “I think a true best friend should be somebody that—good news or bad news—you want to share it with them.” And when you do share, they’ll be there to listen.

It’s good to be friends with people who have different perspectives and backgrounds, but Bonior also believes the “same values in life” help with the best friendship. “You don’t have to be exactly like the person,” Bonior said. “But you have to have enough in common that makes you want to do some of the same things at least.

And that you find some of the same things important—whether it’s the ways you spend your time, hobbies, or values. I think there has to be some overlap there.” After all, some common ground is probably how you ended up friends in the first place.

Just because you may have similar values doesn’t mean your lives are the same. “Ultimately, if we want our friendships to survive and have history, we are just going to have to get very comfortable with saying, ‘Our job isn’t to have the same experiences,’” Nelson said. She notes how people in great friendships don’t have to have certain things in common, like age, political views, or even life events. But what’s important in these cases is staying in touch and connecting through the different experiences.

So, if your friend has become a mom and you don’t have kids, Nelson said you can ask questions like, “What does it feel like to be a mom? How is it different from what you were expecting it to be? What’s been the hardest part? What does our friendship need to look like now?” She mentioned that this is an example of practicing “active vulnerability.”

Even when you don’t have a shared experience with a friend, Nelson explained how you can create “positive feelings.” She gave an example of how she’s not a mother, but she shows positive support for her friends who are. “I send Mother’s Day cards to my girlfriends who are moms every year and just say, ‘I love what a great mom you are. It’s one of the things I admire about you.

I love how you’re doing it. I’m cheering you on,’” Nelson said. “So you don’t both have to be mothers, but what they need is to not feel like that’s a taboo subject or that I’m not interested or that I don’t appreciate how hard it is. Up the positivity and up the sharing. Affirm them, point out things you’re seeing in them, and ask questions. Anything you can do to help make that subject not taboo and be proud of it in their lives.”

The same applies if your friend has a different focus in her life, for example, work or dating. “We both have our things and that’s okay. We just need to use this as an opportunity to get to know each other in this new way,” Nelson added.

Both Bonior and Nelson mentioned that life transitions can threaten a friendship. But the best friendship can last through these changes when you put effort into maintaining and growing it. “You have to be prepared that a life transition will change your friendship and it will take more effort.

Maybe it used to be that you saw each other equally all the time and you have to make more effort to get together because it can’t be as spontaneous as it was,” Bonior said. “You have to be prepared for and you must be realistic that you’re going to have to put forth some extra effort. If both of you are willing to put forth the effort, I think the friendship can grow.”

Nelson went back to her three main criteria for a good friendship when it comes to making an effort. “You don’t just meet somebody and all those three things are instantly in place,” she said. “Even the people that friendship seemed effortless with, you still had to build your own patterns, figure out what you’re going to do together, how often you’re going to do it together, get to know each other. We still had to learn those things.”

So while “effort” might make it seem like you’re trying too hard to make a friendship work, it can be a sign of just how much you value one another through life’s changes.

“Reciprocity is important with best friends,” Bonior said. “It’s really important that both people, overall, feel comfortable with the balance of who’s giving and who’s getting. Because if you’re giving too much or getting too much, that leads to resentment and frustration over time.” She clarified that there may be fluctuations with this, especially if you or your friend is going through a rough spot, but she said it should “roughly even out over time.” This makes sense since no one wants to feel like their best friend is using them.

Sure, you may have joked about marrying your best friend, but Nelson compared the best friendship to marriage because you have to work on it. “With our closest friends, we will have gone through conflict and disappointment with each other. It’s like a marriage,” Nelson said. “We’re not expecting marriage to be conflict-free. A healthier marriage means they handle conflict well and they go through it—and that should be similar for our friendships.”

Nelson added, “We don’t model that well in our culture and we tend to kind of just walk away when there’s drama or hurt feelings. But in an ideal situation, our closest friends should be the people that we practice having those conversations with when we get hurt or disappointed or have unmet expectations.”

“I think at some point, friends can become family,” Bonior said. “You might have a friend that’s in such a different stage of life that if you were to have met them now, you might not have had room for each other in your lives because they’re so different and you wouldn’t have overlapped.” But she noted that shared history keeps you connected just like family—so feel confident when you stop by for Thanksgiving next year.

Just like with a spouse or with family, you’re going to fight. And if you overcome those conflicts, that’s actually a really good sign for your friendship. “It’s not a matter of not having the conflict, it’s a matter of being able to communicate and work through the conflict. It’s probably not the best friendship if there’s never been hurt feelings along the way because two human beings are going to hurt each other occasionally, even if they don’t mean to,” Bonior said.

The key is, as The Beatles would say, to work it out. “So in a good best friend, you can talk about that and allow yourself to bring up difficult stuff. And you respect each other enough to learn each other’s feelings and to empathize and to listen and to try to find a way forward. A friendship that dies just because one person does something that offended the other person and now it’s over, that wasn’t a solid friendship, to begin with,” Bonior added.

It can be difficult to bring up when you’re hurt. “There’s some awkwardness at times,” Bonior said. “You have to have a difficult conversation every once and a while because your friend hurts you and you don’t want to rock the boat.” But if this is your best friend, you realize the importance of talking about it.

“I have seen a lot of friendships die because somebody did not want to bring up that their friend upset them, so they don’t say anything and they swallow it so long that the next thing you know, they don’t like that friend anymore,” Bonior said. “But if they would have said something way back when then the friend would have been able to maybe change the path of the friendship and things would have been able to be salvaged.”

Nelson also mentioned the benefits of hashing things out. “Even conflict is an opportunity for us to learn more about the other person,” Nelson said. She added that the goal of friendships should be to “see our friendship as not needing the other person to reflect us—but to know us.”

Sometimes you’re having a dilemma that you want your BFF to weigh in on, but maybe they’re a bit too occupied to give you the support you need. “There’s a whole bunch of reasons why our close friends can’t be there for us all the time and it has nothing to do with them wanting to be malicious or to disappoint us,” Nelson said, listing things like friends getting married, having a baby, traveling for work, or caring for an aging parent. So just because your best friend might not have been able to 100% support you, it doesn’t mean they aren’t your bestie.

Nelson also suggested that you can spread the supportive friend responsibility out. “If you’re feeling frustrated that your friend isn’t ‘there for you’ in the way you want them to be there for you, it’s often a sign that you should ask yourself, ‘Do I have enough friends in my life?’ It’s often not the fault of that one friend for not being everything and it’s often an invitation to us to make sure we build more support into our lives,” Nelson said. And a good best friend wouldn’t be threatened by that either.

Bonior mentioned that you might feel emotionally drained due to supporting your friend—but again, that doesn’t mean the end of a friendship. “If you feel drained every once and a while because your friend is going through a hard time, that’s okay,” Bonior said.

Yet, she made it clear that this draining feeling should not be constant, and if it is, you may need to evaluate the friendship. “If it’s chronically still draining or you view it as a chore when you hang out with this person, that’s a sign that it’s not really a good friendship,” she added. “There are some friends who complain about everything all the time, they take offense to everything, and they turn everything into drama—that’s not a good friend.”

This may seem really basic, but it’s actually one of the main factors of the best friendship. “One sign that’s often overlooked is just that you like spending time with the person, that you look forward to it,” Bonior said.

“Research shows we have to have five positive interactions for every negative interaction with a relationship to keep it healthy,” Nelson added. “So hopefully, with our closest, healthiest friendship, we are leaving their presence having been affirmed, laughing, gift-giving, being goofy together, having moments of inspiration together—anything that leaves us feeling positive feelings as opposed to feeling judged, competitive, or passive-aggressive.

“At the end of the day, every single one of us wants to enjoy the people we’re with,” Nelson said. And that’s kind of what having a best friend is all about—enjoying time with a person who really gets you. So even though you may be in different spaces, you can look back on this list and be reminded of all the wonderful ways you and your best friend have cultivated your friendship—and how you’ll continue to be there for each other through thick and thin.