You can be yourself around your partner.
If your partner accepts your true self without reservations and doesn’t look to change you, only encourages you to be better, you’ve likely found a good one. Because the reality is there’s no point in being with someone if you often fear that they will judge you, if you can’t act yourself or speak freely because of how they might react. You will never truly be comfortable in that type of relationship, and in turn never truly be happy.
Your partner is usually the first person to call.
When we get good news or even bad news, there’s usually a specific person or persons that spring to mind. These are people you love sharing news with because you know they actually care about what’s going on in your life. These are people you know you can confide in, people who won’t judge you, people who can help guide you. If your partner is on that list, then that’s a big indicator that he or she is a good one for you, an important and valuable part of your life.
Your partner does the little things.
Really caring about someone and being loyal to them is not just about doing the big things: trusting them, being honest with them, not sleeping with someone else, not disrespecting them nor neglecting them. It is also about doing the little things: It is about telling them good morning before checking your phone. It is about grabbing their favorite snack on your way home without them asking. It is about telling them "I love you" on a consistent basis.
It is about occasionally running errands they didn’t get to do that day. It is about asking how their day went and actually listening. It is about being willing to try something new with them. If your partner not only does the big things but also makes an effort to do the little things, then that’s a great indicator that your partner cares about you and your overall happiness.
Your partner isn’t shady.
This is probably the biggest indicator you have a great partner. A partner who doesn’t give you a reason to be suspicious. When someone actually cares about you and is truly afraid of losing you, they do not exhibit shady behavior. They are considerate and care about your feelings. So, they don't come home late with poor excuses. They don't hide their phone from you as if it's radioactive. They don't go MIA. They don't feed you a bunch of lies and expect you to believe them because they see you as someone who is completely gullible and inferior.
They don't do any of these shady things. Why? Because they worry when you worry. Because they care about you. Because what matters to you matters to them. Because they actually fear losing you. And most importantly, because your happiness is important to their own. That’s a great partner!