The Split tool is extremely useful cutting and splitting objects. For example you could use…
Vectorworks Tip #048 – Basic Tools – Contextual Menu
The contextual menu is accessed when you right-click. If you right-click on an object you will get a menu that shows commands appropriate to the object, if you right-click in an empty part of the drawing you will get a different menu. The menus will change depending the objects you click on. The contextual menu is often the quickest way to access commands.