Lay the negi horizontally in front of you and cut vertically between 1-6cm thick depending on the use.
Diagonal (naname-giri)
Position the negi horizontally in front of you at about a 45-degree angle. Slice approximately 5mm-2cm thick.
Finely chopped (miji-giri)
Place the negi horizontally on the chopping board and cut to your desired length.
Hold the end opposite to your knife-holding hand. Make horizontal slits through to the middle of the negi, leaving the top part you're holding intact.
Repeat all the way around until it resembles a tassel.
Thinly cut the "tassels" to finely chop.
Small slices (koguchi-giri)
Hold a bunch of konegi (thin green onion) together and line them up so the bottom makes a straight line. Slice to your desired thickness. (If using 1 negi, cut it into quarters or sixths and line them up before slicing.)
Thin strips (sen-giri)
Place the negi horizontally on the chopping board and cut off a 5cm piece. (2 inches)
Rotate it so it's now vertical and slice through to the middle.
Remove the outer 2-3 layers.
Flatten the layers out on the chopping board and slice them into thin strips.