There are few things which make your post or comment appear unprofessional so much as misuse of the humble apostrophe. This is in large part because it’s so easy to get it right. Here are five rules for use of the apostrophe:
- If you mean “it is,” or “it has,” write “it’s.” Otherwise, write “its.”
- Contractions (can’t, I’ll, you’re) always use an apostrophe, replacing the omitted letters.
- Possessive nouns always use an apostrophe.
- Possessive pronouns (hers, yours, ours, etc.) never use an apostrophe.
- One never forms a plural by adding an apostrophe.
For a deeper exploration of this, including rare exceptions, see my 2008 document, “The Use of the Apostrophe in the English Language.”
This Knowledge Base article was written by John Walker.