To teach tai chi as a complete martial art, you must be more than competent, more than expert.
In our school, instructor training takes place after you have passed 3rd dan.
Teaching the art requires you to transcend the norm, to exceed your expectations, to be mastered by the art itself.
In modern culture too many people adopt the mantle of instructor prematurely. Their combat skills are shoddy, and 4 ounces, softness, jing and neigong are not utilised in their practice.
If you want to be an instructor, you must have something to pass on. Something that adheres to the tradition, but also more than this... something that comes from you, from your own experience of the way.
Beyond instructor there are more grades. These are reserved for those who are scholarly and innovative. People who can comprehend, dismantle and re-build in original and surprising ways.