LOL It's a difference between Army and USMC names in Basic Training. In both services they are Sgt. In the Navy the E-6 or E-7 in charge of the recruit company is called a Company Commander even though his rank is either First Class Petty Officer or Chief Petty Officer. In basic you call him Sir. Come to think of it I think Marines call the SGT Sir in basic training so it might be the Army that has to say Yes Drill SGT or No Drill SGT in boot camp.
But in Full Metal Jacket, Gunny INSISTS on "sir, yes, sir"?
Is there a difference in the Army Vs. Marines?