A good way to summarise is this:
I show the technique eg kote gaeshi the wristlock
You pair up with a partner and practice the technique on him.
If you are unsure of something, angle, position, footwork, then ask me and I will clarify.
Most of the time in class I will come round and correct people and improve their technique.
Sometimes I will call out an instruction to the group eg "step don't stretch".
When it is your partner's turn it is your job to receive the technique and allow him to practice.
It is NOT your job to show him the move or to correct him.
Maybe you think he is doing it wrong - but perhaps he is right and you are wrong, perhaps you are both wrong.
It is NOT your concern how your partner performs a technique - concentrate on your own technique.
To quote Jesus - remove that plank of wood from your own eye before you try removing a speck from your partner.
And you will know if you are ready to "teach" - because I'll give you a black belt.
If you are not yet a black belt then concentrate on getting your techniques right so you can earn the black belt.
Don't worry about your partner's technique - that is between him and me, nobody else.
