Inset the tip of the needle next to where the wool is coming out of the fabric. Not too close but a few millimeters from the exit point.
Keep your right index finger on the wool around the needle so it won’t become too loose.
Use your left hand and push the thread, that is around your needle, DOWN TO THE WORK, hold it there. With your right hand, push the needle all the way to the BACK of your work. Pull the wool through.
Take a peek under your left finger….a French knot!!!!!!