Apostrophes. Basically, apostrophes show possession. For example, “Erickson’s study”, this study belongs to Erickson. Erickson conducted this study, so I need to use an apostrophe “s.”
They can also be used for a plural possessive. By that I mean that, something belongs to more than one person. “The researchers’ methods were sound.” If I’m talking about more than one researcher, then this word needs to be both plural, and needs to include an “s”, and it needs to be possessive.
So the apostrophe actually goes after the “s” instead of before. If I were to put an apostrophe before the “s” I would just be talking about one single researcher. Little tip down here, you don’t need an apostrophe to make a date plural. So I very often will see students say things like “the 1980’s”, or “the 1950’s”, or the you know, “the 1800’s” or something like that and include an apostrophe before the “s”.
That’s not necessary because the dates are plural, but they’re not possessive. In other words, you’re not saying anything belongs to those years so you don’t need an apostrophe. And you don’t need an apostrophe either to make a word plural. “Crop tops” here.
I’m not saying anything belongs to the crop top, so I don’t need an apostrophe.
[Source: Walden University. https://academicguides.waldenu.edu/c.php?g=465757&p=3437920 ]