They are each on a point on the grid. The points have coordinates written as (x,y).
The number horizontally, on the bottom of the grid are the x values. The numbers vertically, going up are the y-values.
So,
O has coordinates x = 1 and y= 1 so it will be (1,1)
E has coordinates x=1 and y = 11 so it will be (1,11)
T has coordinates x=2 and y = 5 so it will be (2,5)
So on…