My last name is Calandra and live with my parents. I am making new return address lables. Should the first line be The Calandra's or The Calandras?
If the word (the family name) is being used as a plural (which it seems to be in this case) then please don't use an apostrophe. Say "The Calandras" on labels, signs or whatever. Otherwise you will annoy sticklers like me.
A. The 70's was a great decade for music.Doing it without the apostrophe is fairly new, and I can't fault anybody (me, for example) for using the first one (A).
B. The 70s' was a great decade for music.
C. The 70s was a great decade for music.
(I was spot on with the rest.)