How could you make weapons if stranded on a desert island?

If you have a knife or sharp-edged stone you can carve a spear, using a shaft of wood at least six and a half feet long. If you have some plants that can be processed to make cordage, and a medium to large pointed thin stone, you can lash on a spear head shaped stone, or even your knife, to the top of your spear.

You can take a sawed off branch and split it two-thirds of the way down the shaft, or instead use a naturally forked branch, and lash a hammer or ax head-like stone into the split or between the forks of the branch. In making this type of hammer wrap tight lashing to well above and below the stone in the split you made, or well above and below the forks. A simple large and hard stick makes an Excellent club.

You can use your shoe strings and a small piece of fabric ripped from your shirt or other article of clothing to make a stone sling.

There is a number of weapons and other tools that a Survivor on a desert island could improvise.