To sail - sailor
to connect - disconnect, connection, connector, connecting, connected
to educate - education, educating, educated, educator
to build -rebuild, building, builder
to create - creator, creature, creating, created
friend - friendship, friendly
leader - mislead, (mis)leading, leadrership, leader
fellow - fellowship
dark - darkness, to darken, darkly
weak - weakness, to weaken, weakly
cold - coldness, coldly
bright - brightness, to brighten, brightening, brightly
free - freedom, freely