Thou knowest my unskillfulness; teach me the wondrous things out of Thy law and heal me.

The amount of jagged dark line which then will mark the limits of the squares will be the exact measure of your unskillfulness.

The unskillfulness of the cook causes frequent vexation and occasional indigestion.

The meat was brought on again, sliced in a manner which could not conceal the unskillfulness of the original attack.