Communion on the tongue; it frightens many Catholics, and makes others a bit nervous. Most of those who practice it regularly know how it works and are likely doing fine, but if they have never received any specific instruction, then there is a potential of room for improvement. Certainly, anyone who receives communion on the tongue is likely more concerned than most with the need to show reverence to the Sacramental Christ, so they will wish to be sure that they are doing so in the best manner possible. So then, with no particular person or error in mind, here is a basic tutorial for how to receive communion on the tongue. You may have already read something in this regard, but please consider the points that are made here.
There are three things that you need to be attentive to: the "shape" of your tongue and mouth, the position of your head, and how much you move. First, there are a few mistakes that new-comers make, and positioning the tongue and mouth are usually involved. I want everyone to think "basketball hoop" and not "coin slot". Holding your mouth open only a small amount means that the priest is needing to "insert" the host between your teeth, rather than to place it on the tongue (which is always preferable). If the mouth is only open a small amount, then your tongue will be "hiding" inside and is not easily reachable by the priest (who really does not want to touch your tongue, lips, or teeth, any more than you want him to).
Additionally, your tongue should be laid out flat on your lower lip. A "flat" tongue is an easier space for the priest to place the host. There are some who stick their tongue out and "point" the tip of it, thinking that this will make it easier, but it actually has the opposite result. A tongue with a "rounded" tip, laying flat on the lower lip acts like a "landing pad", whereas a stiffened tongue with a pointed tip acts like a "landing strip". The difference is that the host sits and remains more easily on the wide and flat tongue than it does on the thin pointed tongue. Therefore, there are far more occurrences of the host falling off the pointed tongue than of the flattened tongue. The only time I ever had a host fall off of a wide flat tongue was when the person had a very dry mouth and pulled his tongue in quickly, thus forcing the host to fall off.
Second, we have to consider the position of the communicant's head. A head that is leaning forward causes the tongue (even if laying flat and wide on the lower lip) to be more in a vertical position than horizontal. Therefore, if the tongue is in the least bit dry, the Sacrament is likely to fall off. This means that it is best to hold the head tilted back just a bit so that your tongue is closer to a horizontal position. You, obviously, do not want to tilt your head so much that the priest has to "reach over" your chin to serve the host, but just enough so that your eyes are about at a 45 degree angle to the priest (as though looking toward his eyes when he says "the body of Christ").
Finally, there is the factor of the movement of the head. Even if the above two points are followed, but a person moves his head (either wobbling or "jutting" it forward towards the host) then the host can still be knocked to the ground because the priest is having to "hit a moving target" (not fun--trust me). Please work to keep your head stationary, and let the priest bring the host to you. Certainly, there are some older folks who have health issues that make them shake, but the priest can usually tell that is the case and he can deal with it. If he presumes that you do not have any such health issues then he will also assume that you are going to stay in one place.
The only factor that can influence the head movement is if an altar boy is not holding the hand-paten directly under your chin. Technically, even with all the above "rules" followed, accidents can still happen (we do live in a fallen world). So the hand-paten is the "catch all" (pun intended) to make sure that the host does not touch the ground. Therefore, if the hand-paten is not directly under your chin, do not open your mouth until you see it moving in that direction. I once had someone move his head at the last second to get his chin over the paten, and that caused me to "bump" the host on his tongue, and it bounced right back out of his mouth.
With all this said, I must make it clear that these are merely suggestions gleaned from years of serving communion on the tongue. There may be other suggestions that a different priest may make, but these seem to work the best for me. Consider these helpful points, and--to make it easier for you--practice beforehand; you can do so in a mirror at home, but it is not best to wait until you get to the rail and try to remember all that was said here (and parents, help your children to prepare!). This way you will be ready to receive Christ in the most reverent and godly manner.
