yes
Some did.
Sub-machine guns, rifles, grenades, Panzerfausts, and Panzershrecks.
the machine guns
No, machine guns were typically carried by a machine gun team. An officer seldom carried a machine gun and normally a pistol and perhaps a carbine. Some may have been able to get a sub-machine gun.
Yes, they did have machine guns in WW2
Yes. There were machine guns in WW1. There were Gatlin Guns, a type of machine gun, in the Civil War.Yes
During World War II the United States used a couple different sub-machine guns such as the M3/A1 "Grease Gun", the infamous Thompson sub-machine gun the M50/55 Reising the M42 and the M2 "Hyde."
Machine guns were in use BEFORE WW 1. They were around for the entire war.
No
Most of the parties involved already had machine guns in their inventory prior to the outbreak of the First World War.
All of the major players in WWI possessed machine guns before the outbreak of the war.
In World War 2 there were three types of machine guns used: squad support weapon, medium machine gun, and Heavy Machine gun such as the Browning M2, and the M1919