Possessive pronouns show ownership or association between a pronoun referent and a noun. They are one of the most frequently used grammatical structures in English and one of the areas where several common errors cluster.

What possessive pronouns are

A possessive pronoun replaces a noun phrase consisting of a possessive determiner and a noun:

instead of my book, the possessive pronoun mine stands alone. The possessive pronouns in English are:

Person	Singular	Plural
1st	mine	ours
2nd	yours	yours
3rd masc.	his	—
3rd fem.	hers	—
3rd neut.	its	—
3rd plural	—	theirs

These are sometimes called independent possessives because they stand alone without a following noun: That book is mine (not That is mine book).

Possessive pronouns vs. possessive determiners

A common point of confusion is the difference between possessive pronouns (mine, yours, his, hers, its, ours, theirs) and possessive determiners — sometimes also called possessive adjectives — (my, your, his, her, its, our, their).

The distinction is syntactic:

     Possessive determiner (modifies a noun): This is my research. / Their results were unexpected.

                  Possessive pronoun (stands alone): This research is mine. / These results are theirs.

Note that his and its serve both functions — a fact that sometimes creates confusion about whether other forms (mine, yours, etc.) can modify a noun. They cannot: That is mine book is ungrammatical.

The critical error: “its” vs. “it’s”

Its (possessive determiner, no apostrophe) and it’s (contraction of it is or it has) are among the most commonly confused words in English writing.

The study has its limitations. (its = belonging to the study; no apostrophe)

It’s a well-designed study. (it’s = it is; apostrophe marks the contraction)

The rule: possessive pronouns never use apostrophes. Yours, hers, its, ours, theirs — none of them take apostrophes. An apostrophe in it’s always signals the contraction it is or it has, never possession.

“Their”, “there”, and “they’re”

A related and equally common confusion:

their: possessive determiner (their findings)

there: adverb of place (the data is stored there) or expletive (there are three conditions) they’re: contraction of they are (they’re the most cited authors)

Gender-neutral singular “their”

The use of their as a gender-neutral singular pronoun (Every participant submitted their consent form) is now widely accepted in formal and academic writing. It resolves the awkward his or her construction without requiring the writer to assign a binary gender to an unspecified individual.

Trinka’s grammar checker identifies its/it’s errors, their/there/they’re confusions, and other possessive pronoun errors in context.

References

Garner, B. A. (2016). Garner’s Modern English Usage (4th ed.). Oxford University Press.

American Psychological Association. (2020). Publication Manual of the American Psychological Association (7th ed.).