How do calligraphy teachers comment on students' calligraphy works?

First of all, it points out the maze from the brushwork, including starting the pen: the angle of entering the pen and the speed of hiding the pen; Brush: It mainly refers to the ability of lifting, pressing, folding and twisting: there are three aspects of folding, falling and hiding, followed by writing, such as size, Fiona Fang, forward and backward. Secondly, the understanding of the post, what can be learned from the post, can be seen from the homework, and need to be pointed out to the students. Thirdly, the control ability of the pen.