"A well-regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
Most people today assume that the Framers were just ignorant slobs who left this awkward phrasing in the Second Amendment in their precipitous rush to Get Something Done. I find that unlikely. I believe the Framers composed the Second Amendment with perfect grammar to say exactly what it means. The phrase, "being necessary to a Free State" is clearly a subordinate clause explaining the use of a well regulated Militia.
The Second Amendment therefore says, "A well-regulated Militia, the right of the people to keep and bear Arms, shall not be infringed."