If it is a proper noun and ends in “s” then add an ‘s. Be consistent.
Incorrect the essays author
Incorrect Charle’s friend
Incorrect Burns’ poems
Incorrect the witches malice
The pronominal possessives hers, its, theirs, yours, and oneself have no apostrophe.
it’s= it is
its=possessive
Notice the difference an apostrophe makes:
Are you looking at my footprints or the wolves?
Correct: Are you looking at my footprints or the wolves’?
(The correct sentence implies that the observer is looking at humn and wolf prints, while the first sentence implies that the observer is looking at human footprints and actual wolves.)
Principle: apostrophes indicate time or quantity:
Ex= ten gallons’ worth or two weeks’ notice
Principle: apostrophes eliminate letters or numbers
Ex= I should’ve read Writing Across the Curriculum Guide.
In the aftermath of the fall of ’01, national security became a priority.
Principle: apostrophes indicate the plural of letters and words:
Ex= The alliteration of w’s in “(t)here never was a sound beside the wood but one” is calming. How many and’s are there in this poem?