This is fairly self-explanatory.
But notice there are 2 parts to this
FIRST - Were directions clear and given in good time
Are they clear and concise – For a newer pupil to say At the roundabout take the third exit – Is that straight ahead third exit, right 3rd exit? – Unless you are working on road markings and signs it is more likely to cause confusion for the pupil.
Or of course suddenly shouting turn left here!! And then telling the pupil that they didn’t do the MSPSL routine!
Second - Were the Instructions clear and given in good time?
To say to a pupils check the mirrors or Dont forget to do mirror, mirror - isn't clear - do you mean centre and left or centre and right?
"Steer!!" - Do you mean turn the wheel a quarter of a turn, half a turn, do you want me to think of it as a clock and steer 10 oclock, 2 oclock 12 o'clock - what is it that you actually mean?
A great way to work on this is by recording yourself and listening back to it. It is amazing what people think they say.
Remember pupils will often need a couple of extra seconds to think which is left and which is right