The apostrophe-s ('s) is primarily used for two purposes in English:
- To form possessive nouns:
- For most singular nouns, add apostrophe + s to show ownership (e.g., "dog" becomes "dog's" to indicate something belonging to the dog, like "the dog's ball").
- For singular nouns that already end in "s," it is generally preferred to add apostrophe + s (e.g., "James's book"), though some style guides allow just an apostrophe (e.g., "James' book").
- For plural nouns that end in "s," add only an apostrophe after the s to form the possessive (e.g., "parents" becomes "parents'" in "my parents' car").
- For plural nouns not ending in "s" (irregular plurals like "children"), add apostrophe + s (e.g., "children's dinner").
- Use apostrophe + s also for proper nouns, acronyms, and compound nouns (e.g., "the BBC's funding," "his brother-in-law's motorbike").
- To indicate contractions:
- The apostrophe replaces missing letters in contractions, such as “it’s” for “it is” or “it has.”
- This use does not indicate possession.
Important notes:
- Do not use an apostrophe to form plurals (e.g., "mangos," not "mango's"), except when pluralizing individual letters for clarity (e.g., "two e's").
- Possessive pronouns (e.g., my, your, his, its) do not use apostrophes to show possession.
- When a singular noun ends in "s," style guides generally recommend adding 's (e.g., "Darius's reign"), but some permit just an apostrophe.
- In expressions like "for goodness' sake," the apostrophe is used without an additional "s" for easier pronunciation.
In summary, use apostrophe + s to show possession for most singular nouns and some plurals, and to form contractions indicating omitted letters. Avoid apostrophes when simply making a noun plural.
