Use of the apostrophe has crept into pluralization, even in basic words (“he jump’s in”). I suspect the creeping is born of the ongoing uncertainty about when to use “it’s” versus “its”, and so I offer the following to clarify.
Plural
We can get this out of the way first – plural is plural. No apostrophe needed.
It’s
Apostrophes are used to indicate that letters have been removed from one or more words to form a contraction (for example, “cannot” becomes “can’t”), and to indicate possession.
“It’s” is a contraction of “it is”, and is never a possessive word. If you can use “it is” in your sentence in place of the contraction “it’s”, then “it’s” is the word you need.
Example: “It’s harder to see the stars at night in the city.”
Test: “It is harder to see the stars at night in the city.”
The test sentence works, so the contraction “it’s” is the word you want.
Its
“Its” is a possessive word that doesn’t take an apostrophe. No wonder we get confused, especially when the word “it’s” is available. It may help to remember that “its” has grammatical cousins: “his” and “her” are also possessives that don’t require an apostrophe. This relationship gives us a second test option, but the test we used above is likely all you’ll need.
Example: “The trailer lost its wheel.”
Test: “The trailer lost it is wheel.”
The test sentence doesn’t work, so you don’t need the contraction “it’s”. The possessive “its” is indeed the word you want.
The second test is more limited as it works best with living subjects. Try “his” or “her” in place of your word. If that works, then you’re using the possessive “its” correctly.
Example: “The dog moved its dish closer to the bag of food.”
Test: “The dog moved her dish closer to the bag of food.”
The test sentence works, so “its” is the right word.
Lisa Harrison Communications 