What do we mean precisely when we call somebody a friend? I suspect that is one of the most misused words in the English language since there are at least 4 different types of friends.

1. An acquaintance is somebody you encounter in your regular routine, whether at school or at work, a neighbor, a parent of your children’s friends, or somebody you see regularly at church or a place you volunteer occasionally. You are glad to see that person, and you happily spend time talking with them, but–and this is the important part–you do not make deliberate plans to share time with that person outside of the usual place where you encounter them. That makes them an acquaintance rather than a friend.

2. A casual friend can be somebody you talk with, but rarely socialize with. You are more likely to exchange email with them, or facebook, or occasionally IM. Perhaps an occasional phone call, but rarely. You may “get together” a few times a year, or see them at conferences, but hardly otherwise. These are certainly closer than acquaintances, because you do go out of your way to share an activity with them, but they are not the person you normally “hang out with” on weekends except on rare occasions.

3. A close friend is somebody you do spend time with on a fairly regular basis. Speaking on the phone, meeting for dinner, going to the mall, hanging at their house for a few hours, chatting online regularly. These are the people you look forward to seeing, and your conversations tend to be more revealing of your true selves and emotions than with either acquaintances or casual friends. You spend a greater portion of your free time overall with close friends than you do with anybody other than your nuclear family (parents, spouses, children).

4. A soul mate is the rarest of friends, somebody who emotionally is like an unofficial member of your nuclear family. You share your deepest feelings, values, and emotions with them. When you are happy, that is the person you share it with. When you are unhappy, they are there to console and advise you. You might not even spend as much physical time with a soul mate as you do with a close friend, but time is not the factor here; sharing is the key.

Some comments on the various types of friends:

• The numbers of people in the various categories decrease as you move down the list. We tend to have more acquaintances than casual friends, more casual friends than close friends, and only 1 or 2 soul mates if we are lucky. Some people have no soul mates their entire life;

• People in the first three categories are an ever-changing group. A close friend in high school might totally fade away in college. Acquaintances are totally dependent on your job, where you live, what activities you engage in, so they change with every change in your life;

• It is possible that somebody you consider a close friend only considers you a casual friend, and while there is often no enjoyment lost by those differences in categorization, the possibility of a friend fading away is more likely in a “one-sided” friendship;

• You are more likely to maintain a longer, richer relationship with your spouse if they are also your close friend. While it is possible for a spouse to also be a soul mate, often a spousal relationship is stronger if you have an additional soul mate as well, since no one friend can share every single aspect of your personality (each value, interest, emotional state), so having both a spouse and a soul mate strengthens both relationships.

Now some personal observations on my own life:

• As a teacher, I am friendly with several fellow teachers, but they are mostly acquaintances because none of them have any contact with me outside of school. There is only one former fellow teacher that I ever socialize with, and that is on an occasional, once-or-twice-a-year basis, so he and his wife are casual friends;

• I deliberately stay in touch with several of my former students, and several of them reply to my emails and occasionally IM or facebook me. With a few exceptions they are casual friends (although valued ones, but value is irrelevant to the level of a friendship). In fact, the majority of them likely consider me an acquaintance since I initiate nearly all the contact and they only reply, if at all, when they hear from me;

• I published a monthly magazine with a readership of about 100 people. I have some type of interaction with nearly all the readers, all of it some type of written exchange. Since all this interaction is totally voluntarily, I consider all my readers casual friends as well, even though I have only ever met at most a small handful of them in person;

• How many close friends do I actually have? My wife and I are very friendly with one couple, and there are a few former students whom I chat with regularly, one almost daily. Other than that, I cannot think of anybody that I spend considerable free time with, whether in person or online. I realize that some people probably have at least 6-12 close friends, but I have always been somewhat of an anomaly socially;

• Soul mates are too personal to discuss in public!