Marriage and relationships are hard work. We know, but do we truly understand it?

If we're not careful, we can turn even a loving relationship into a toxic one just by cruising along and assuming everything is fine. It can be hard to tell when your relationship has crossed the line from healthy to unhealthy.

Next thing you know, your partner is miserable, and you and you are shocked and caught unaware. After all, you thought everything was fine! But did you ever stop to ask them the questions they need to hear so you can find out how they feel? Probably not!

Simply asking someone, "Do you love me?" or "Are you happy?" will not get the job done. No, you need to get deeper. But how?

Senior VP of YourTango Experts, Melanie Gorman, asked a group of big-name Experts what questions a couple who wants to test the health of their relationship should be asking. And our Experts — Chris Shea, Sharon Davis, Nancy Dreyfus and Stan Tatkin — did not disappoint.

Here are 8 questions that will change the entire trajectory of your marriage:

1. "Do you feel like you get to be your real self around me?"

Relationships are when two people love each other and want to be with each other. But if you and your partner feel like you can't be yourself, it can't be real love because they can't know the real you, as shown by a study in Personality and Individual Differences Journal.

Ask, "Am I being my real self in this relationship?"

2. "Is there anything you feel like you have to hide from me?"

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If you or your partner feel like they have to walk on eggshells around the other, that's not good.

After all, a good relationship is all about honesty, and if you have to start hiding things from your significant other, there's something wrong.

3. "Who is the person you go to for comfort, celebration, or anything exciting in your life?"

Your partner should be your rock, and you should be theirs. Studies published in the Journal of Personality and Social Psychology support how they should be whose shoulder you cry on and the one to dry your tears.

The one to fight for you and defend you. Your partner should be the one to make you laugh until you cry and the one who takes your breath away. Your partner should be the first person you want to tell whenever anything happens to you, be it good or bad.

If you are not that for them, you should find out why so you can become their rock and their true home.

4. "Do you put the relationship first?"

This is perhaps obvious. But there are people who, because of their past and their culture, have learned to put themselves first. Are you one of those people? Is your partner?

5. "What do you love about this relationship?"

Sometimes, we marry our partners because we love them, and sometimes because we love how we feel when we are with them, as supported by research in the Current Psychology Journal. There's a difference between like and love, and it's important to know which you feel for the marriage to have a chance.

6. "Do you know what I need and like? Do I know what you need and like?"

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Everyone has a love language that they speak, and what you need to feel loved might not be what your partner needs.

Very often, we don't think about the things that make our day, but take a moment and see if you know your partner as well as you think you do. And if you don't, that's OK, you can learn it now!

7. "Do I know who you truly are? Do you know who I am?"

While it might seem like this has nothing to do with the health of your relationship, it's the most important thing.

Losing your sense of identity in your relationship can do more harm than good, as suggested by research in the Journal of Personality and Social Psychology. You need to know who you are and how your past might affect your relationships (because it usually does in some way).

And you need to know whether you understand your partner's unique identity, too.

That way, when something bothers you, for example, you'll understand why and be able to work on it without feeling resentment towards your partner.

Ask yourself, "Who am I?" If you don't know, how can your partner?

8. "Is there more?"

This one is simple, but it may be the most important one. Say it with love. Be inviting. Make it an opportunity for your partner to hear and see that you want to understand how they feel.

You don't have to wait for the "relationship check-in quiz" to ask this one. Bring it out with a loving touch or kind smile any time your partner is talking about their feelings.

These three words may be the key to building true, lasting intimacy. If you haven't been asking these questions, know that it's not too late — so don't feel like your relationship is doomed. Even if you or your partner answered the questions in a way you weren't expecting, that's okay.

As long as you both are aware of the work that has to be done and are willing to get some guidance, there is no reason your relationship can't go back to being perfectly happy now that you truly understand each other.

The YourTango Experts team includes licensed therapists, dating and life coaches, matchmakers, and more professionals committed to offering you the tools and guidance for a happier and more rewarding life.