Even in preschool, it is natural for boys and girls to develop friendships. While some men and women are able to maintain lifelong platonic friendships, other opposite-sex friendships develop into romantic relationships. If you have a close friendship and aren't sure if it is turning into something more, pay attention. Figuring it out might be easier than you think.

You Tell Each Other Everything

Communication is an important part of any friendship. In a typical friendship, you can expect a call or text from your friend a few times throughout the week. When a friendship is turning into something more, you and your friend will talk every day and have long conversations, sometimes about nothing at all, writes Julie D. Andrews in the YourTango article, “4 Signs You're More Than Friends.” Indeed, when you have a crush on someone, you find any and every reason to talk to them.

You Spend All Your Time Together

The line between friendship and romantic love is thin. Many elements of a good friendship are also true of a relationship. One characteristic that sets friendship and love apart is passion, according to a team of University of Nebraska-Lincoln Extension Educators in the publication “Friendship, Love and Sexual Intimacy.” You can assume that your friendship is turning into love when you become preoccupied with your friend, think about her constantly and have a strong desire to be with her all the time.

You Touch Each Other More

An increase in the amount of physical attention you give each other is a strong indicator that things are moving past a friendship and into something more. If you find yourself holding your friend's hand or putting your head on his shoulder more often, chances are your friendship is developing into a relationship. Examine body position and posture between you and your friend. If you lean forward and face each other when talking, you are subconsciously communicating interest and receptiveness, according to the Psychology Today article, “10 Tips to Create Powerful Non-Verbal Communication,” by Barton Goldsmith, a psychotherapist.

You Stand Up for Each Other

University of Nebraska-Lincoln educators found that caring is another factor that differentiates between friendship and love. When you have romantic feelings for someone, you will support, advocate for and defend that person no matter what. Think about the level of trust and loyalty there is between you and your friend. If she stands up for you, supports your goals and is there when you need her, take it as a sign that your friendship is evolving.