Vocabulary is the foundation to understanding a subject. The same is true with Taijiquan. For now, I am ignoring the translation problem and focusing on the basic vocabulary we need to communicate the Taijiquan routine.
Is the Taijiquan routine a sequence, or a routine? Is a static position a posture or a form? The interchange of the words form, posture, and stance creates confusion. For example, is it the Yang Style Taijiquan form, sequence, or routine? Is that the Ward Off posture or form? Are you in the Bow and Arrow posture or stance?
Stance: In simplest terms, is what you are doing with your feet. The New Oxford American Dictionary defines a stance as “the way in which someone stands.” You could expand that definition to include a posture “you deliberately adopt in sports,” but that is a posture, not a stance. A stance is what you do with your feet, not your hands, head or chest. In the Taijiquan sequence you will assume a few stances repeatedly, each in the expression of a different posture. For example, there is the Horse stance, the Toe stance, and the Bow and Arrow stance.
Pose: My dictionary says that a pose is “a way of standing or sitting usually adapted for effect.” For our purposes, a pose is the stance plus the position of the hands, head, and chest. The body will transition through many poses while expressing a Taijiquan posture.
Posture: My dictionary defines it as “a position of a person’s body when standing or sitting.” That could be a pose, but in Taijiquan a posture is more than a simple pose. There can be multiple poses between postures, a series of transitional movements that end in a final pose that gives the Taijiquan posture its name. Sometimes a sequence of postures are grouped under a single name. Grasp Sparrow’s Tail, for example, groups Ward Off, Roll-back, Press, and Push.
Form: Form and style are used interchangeably. When discussing the various lineages of Taijiquan I will talk about the Yang family style, or the competition forms.
Style: Style is a broader term for the various forms of Taijiquan, but style and form are interchangeable. For example, there is the Yang style of Taijiquan, but within the Yang style there are many forms that originated from Yang, Lu-Chang’s sons and their students.
Going forward, I will stick to the above definitions in my future writings, and not refer to the Heel posture used in the Brush Left Knee posture. Instead, I will call it the Heel stance in the transitional pose of the Brush Left Knee posture.