Pas de Deux
Pas de Deux is French for "Step of Two" and is what partnering is called in ballet. By dancing with a partner the lady can jump higher, take positions she would never be able to on her own, and "float" about the stage as she is carried by her partner. A partner allows a man to extend his line and show off his strength.
In pas de deux the man quite often does not stand in a balletic position or appear to be dancing at all. He can do this because the audience will almost always watch the lady, but now that you have read this I'm sure that you will watch the man as well next time you go to the ballet to see if it is really true. The man acts as a "third leg" for the lady by stabilizing, lifting, and turning her. To see a Quicktime animation of the gentleman leaning the lady back and forth to get used to working with her and then supporting and turning her to an arabesque click here. From the arabesque they could go into a promenade or one of many different lifts that start in arabesque.
Four major areas of technique in pas de deux are promenades, lifts, turns, and jumps, although there are other areas as well. A promenade is when the lady takes a position on pointe and the man walks around her while holding on to her, thus making her turn. A promenade can be done in almost any position and may change positions during the course of its life. You may think that it is pretty simple to do a promenade, how hard can it be to walk around someone? However, the lady must be kept "on her leg" or on balance during the promenade, and this can be quite difficult. A lift is just what it says: The gentleman lifts the lady. The number of different lifts that can be done in ballet is almost limitless. A pair of dancers can do a "fish" where the lady is picked up from an arabesque position and folds her bottom leg up, then is swung back by the man so she makes a curve like a fish close to the ground, or they can do a présage where the lady is lifted in a similar position to the fish but to arm"s length over the gentleman"s head. These lifts are some of the most awe-inspiring moves in ballet and some of the most demanding. When doing turns with a partner it is normally the lady who does the turning, usually some sort of pirouette. When doing a normal pirouette with a partner the gentleman will be behind the lady and will stabilize her and sometimes help her to turn with his hands on her waist. By doing pirouettes this way a lady can do many more pirouettes than she would normally be able to do on her own. Jumps can be very fun, tiring, or scary depending on what kind of jump a couple is doing. Normal jumps where the lady is jumping and the gentleman is simply lifting her to make her go higher do not involve much risk, but can be tiring after a while. These jumps are normally used as a warm up in class and not performed on stage. Some of the more risky jumps would be more accurately described as catches. This would be where the lady jumps on her own into the arms of the gentleman. Probably the most dangerous of these jumps is a leap of faith; this is the jump when the lady takes off and turns in the air so that she will land on her head if the gentleman does not catch her. Such moves always bring a gasp from an audience.