Directional verbs take their name from the fact that they change the direction of movement –and sometimes also of the orientation of the palm or the fingers. This form change depends on what the subject and the object may be.
"I'm teaching him sign language."
"She's teaching me English."
In the first example, the movement goes from the subject –the signer– to the object, which is a third person. But, in the second example, the movement starts in the subject –who is the spot in which we placed the third person– and ends in the object, who is the signer.