The relative pronoun already has a role inside the clause
A defining relative clause attaches to a noun and identifies the thing or person intended. Its introductory word does more than link two parts: it also acts as subject or object within the clause.
This explains why a frequent error can seem natural. A first-language pattern may encourage repeating the thing inside the clause, but English has already filled its role: if the relative pronoun is object, do not add another word after the verb for that same thing.
A simple check is to mentally remove the relative pronoun and look for a gap in the clause. That gap is the role it fills, so nothing should be added to fill the same role again.
noun + that / which / who + clause with one role already filled
- noun —
- A word naming a person, thing or idea: student, book, happiness.
- clause —
- A construction with a verb, often with its own subject: when I arrived. A non-finite clause may leave the subject unspoken: to get home.
The film that we watched on Sunday lasted three hours.
The film that we watched on Sunday lasted three hours.
The relative pronoun is watched’s object, so add nothing after the verb.
The driver who brought the parcel had no change.
The driver who brought the parcel had no change.
The relative pronoun is subject here; no separate he accompanies it.
Three places where a redundant pronoun appears
The repetition occurs in three positions: the verb’s object, the clause’s subject, or the object of a preposition left at the clause’s end.
The error does not depend on the particular relative pronoun: it occurs with that, which and who alike. Correct it by removing the repetition rather than changing the pronoun.
The minimal edit here deletes exactly one word. If the sentence breaks after deletion, the wrong word was removed: the relative pronoun links the clause to the noun and stays in place.
The bench that we sat on was still wet.
The bench that we sat on was still wet.
The object of on is already expressed by the relative pronoun; a pronoun after the preposition would repeat it.
The gardener who plants the roses starts at six.
The gardener who plants the roses starts at six.
The relative pronoun is the clause’s subject and needs no second subject.
Whose and who’s: the same sound, different roles
Whose expresses possession or a relationship before a noun phrase: whose ticket, whose new ticket. An adjective can appear between whose and the head noun.
Who’s means who is or who has. Who is can precede a verb form, adjective or noun phrase: who’s waiting, who’s ready, who’s a teacher. Consider the whole clause’s structure and meaning, not just its next word.
The quickest check is to expand the contraction. If who is creates a nonsensical combination in this position, the possessive form is needed.
The possessive form is not limited to people: it can also connect an organisation, building or city with something associated with it.
whose + noun phrase; who’s = who is / who has (check what follows)
- NP / noun phrase —
- A noun phrase: a noun with its dependent words, such as the new student; the pattern treats it as one group of words.
- noun —
- A word naming a person, thing or idea: student, book, happiness.
The passenger whose ticket was missing stayed at the desk.
The passenger whose ticket was missing stayed at the desk.
Possessive whose precedes ticket, belonging to the passenger.
The passenger who’s standing by the window has the same ticket.
The passenger who’s standing by the window has the same ticket.
The verb form standing follows the contraction, so expanding who is preserves the meaning.
The museum whose roof was repaired last year is open again.
The museum whose roof was repaired last year is open again.
The possessive form is appropriate for a building too, not just a person.
Why relative what cannot follow a named noun here
What itself means “the thing that”: it combines a referent and a relative link. It cannot attach to an already named noun in this standard relative pattern; that would duplicate the referent.
After a noun, English uses an ordinary relative pronoun. In these defining clauses, that and which are natural for things; who and that are natural for people.
First-language interference can make this error persistent: one linking word may serve both purposes elsewhere, but English relative what does not.
The poster that we printed for the festival is still on the door.
The poster that we printed for the festival is still on the door.
The poster is already named, so an ordinary relative pronoun introduces its clause.
The playlist which the café plays in the morning is very short.
The playlist which the café plays in the morning is very short.
For a thing, the alternative relative pronoun is equally correct here.
When what really is appropriate
Without a preceding head noun, what naturally means “the thing that”: What you said was helpful. It combines a thing and its relative link. This does not mean that every clause without a head noun can only use what.
This “the thing that” pattern can therefore start a sentence with what, without a preceding head noun. Adding a head noun calls for an ordinary relative pronoun instead.
The converse check is to replace what with the thing that. If the sentence remains natural, what fits.
What the pharmacy suggested worked in two days.
What the pharmacy suggested worked in two days.
There is no noun before what; the entire what-clause serves as the main sentence’s subject.
We paid for what the printer damaged.
We paid for what the printer damaged.
After for, the what-clause likewise expresses a generalised thing rather than modifying a named noun.
After everything, something, nothing and all
Everything, something, anything, nothing and all already include the sense of a thing. Adding relative what would repeat that sense.
That is often used after these generalising words. Which can also occur depending on construction and style; do not turn a preference for that into an absolute ban. Here we practise that as the basic standard option.
The relative pronoun can sometimes be omitted when it is object, but what does not replace it after these head words in this standard pattern.
Everything that the ferry company promised was in the email.
Everything that the ferry company promised was in the email.
The generalisation already supplies the referent, so one relative pronoun introduces the clause.
Nothing that the shop offered us was in stock.
Nothing that the shop offered us was in stock.
A negative generalisation follows the same pattern as everything.
Minimal correction: fix rather than rewrite
Each of this rule’s three errors needs one action. Remove one word for repetition; replace one word for who’s/whose or what/that confusion.
Rewriting the whole sentence has a practical drawback: you can lose a fact or alter the meaning, making the error disappear along with information.
Identify the error type before editing. Otherwise, it is tempting to “fix” the sentence with an unrelated random change.
The curtain that the shop delivered is too short.
The curtain that the shop delivered is too short.
The version with a redundant pronoun needs only one deletion; all other words remain.
The client whose deposit was returned signed a new contract.
The client whose deposit was returned signed a new contract.
Only the contraction needs replacing with a possessive; facts about the deposit and contract stay unchanged.
Common mistakes
Incorrect:The film that we watched it lasted three hours.
Correct:The film that we watched lasted three hours.
The relative pronoun is already watched’s object; it repeats the same object role.
Incorrect:The driver who he brought the parcel had no change.
Correct:The driver who brought the parcel had no change.
The clause already has the relative pronoun as subject; he duplicates it and disrupts the link with driver.
Incorrect:The hall that we sat in it was freezing.
Correct:The hall that we sat in was freezing.
A final preposition does not change the rule: the relative pronoun already expresses its object, so it is redundant.
Incorrect:The gardener who’s tools were stolen called the police.
Correct:The gardener whose tools were stolen called the police.
Who’s expands to who is, but this refers to possession of tools, so use whose.
Incorrect:The playlist what she made for the trip is still online.
Correct:The playlist that she made for the trip is still online.
Playlist is already named, so use an ordinary relative pronoun; what itself means “the thing that”.
Incorrect:Everything what the pharmacy told us turned out to be wrong.
Correct:Everything that the pharmacy told us turned out to be wrong.
Everything already supplies the referent, so what duplicates it; that is the practised form after this word.