Omitting relative pronouns: when you can leave out who/which/that

1. One sentence, two equally correct versions

In a defining relative clause, who, which, or that can sometimes simply be left out. This is not careless speech or a shortcut made purely for speed: both versions are equally correct and mean exactly the same thing.

The word leaves a gap. No information is lost because the following structure makes the noun's role clear: a new subject with its own verb begins immediately after it.

A translation into another language may use the same relative word for both English versions. Make the choice by examining the English relative clause's structure rather than relying on the translation.

The parcel that we collected yesterday is still in the hall.

That is the object of collected: the parcel was collected, and we did the collecting.

The parcel we collected yesterday is still in the hall.

The same sentence without that. The participants, time, and meaning remain unchanged.

The postcard Marta sent from Lisbon is on the shelf.

The new subject Marta follows postcard directly, so the relative word is optional here.

2. Check the word's role, not just its neighbor

Find the subject of the relative clause itself. If who/which/that is that subject, retain it: the neighbour who often calls. If a subject is already present and the relative word is an object, you can normally omit it: the neighbour (who) I called. An intervening adverb does not change these roles.

The new subject need not be a pronoun. It can be a whole noun phrase: my flatmate, the finance department, Marta. Looking only for I, we, or you can make you miss a subject that is already there.

The noun being described can be either a subject or an object in the main clause; this does not affect the rule. Only the role of who/which/that inside its own relative clause matters.

How to build it

noun + (Ø) + new subject + verb · noun + who/which/that + verb

subject / S: The grammatical subject: who or what the clause is about; the verb agrees with it. In The book was written, the book is the subject, although someone else does the action.
verb / V: A word for an action or state, such as work or be. The pattern determines its form.
noun: A word naming a person, thing or idea: student, book, happiness.

The kettle my flatmate bought boils in a minute.

My flatmate follows kettle and is a whole noun phrase functioning as the subject, so omission is allowed.

The neighbour who waters our plants is away this week.

The verb waters follows who: the neighbor does the watering, so who cannot be omitted.

The van that blocked the entrance has gone.

Blocked follows that, and the van itself did the blocking; the relative pronoun is the subject and must remain.

3. When the word cannot be omitted

If the relative word is the clause's subject, it is the only element showing who performs the action. Omitting it leaves the verb without a subject.

The error creates two predicates without the required connection. A reader may initially interpret the beginning as a simple sentence, then have to return to the start.

This applies to both people and things: who, which, and that behave alike in the subject role. Here, the choice is between who/that for people or which/that for things, not between retaining and omitting the word.

The courier who rang the bell left a note.

Who is the subject of rang. This structure requires it, regardless of who performs the main clause's action.

The alarm that goes off at midnight belongs to the shop.

The alarm itself goes off; the verb follows that directly, so omission is impossible.

The woman who cleans our stairwell starts at six.

Who is the subject of cleans and remains. In the woman (who) we called, the relative clause's subject is we, so object who can be omitted.

4. Leave the object gap empty

When the relative word is omitted, its object position inside the clause must remain empty. Adding it, them, or him is a common mistake: the object is already identified by the noun before the clause.

The same restriction applies when the relative word is retained: in The parcel that we collected it, it is redundant, not that. Repeating the object is a separate error, independent of whether the relative word is included.

Reconstruct the simple statement: We collected the parcel. In the relative construction, parcel is already named before we collected, so do not repeat it with it. Check the object's role rather than whether the verb can ever occur without an object in other contexts.

The shelves we ordered in May arrived without screws.

Do not add them after ordered for the same shelves. The time expression in May stays in place.

The article the editor cut in half still felt long.

Cut has no overt object inside the relative clause because article already supplies that role.

The receipt the shop printed is in my wallet.

The shop printed with an object gap is correct here; adding it would remove the required relative connection.

5. What this rule does not remove

Whose cannot be omitted under this rule: it expresses possession, and removing it also removes the relationship between the two nouns.

Do not mechanically apply the object who/which/that rule to where. For a place, check the required construction: the house where we live → the house we live in. Some phrases also allow a zero form, such as the place we live; that separate use does not make arbitrary omission of where safe.

In a relative clause set off by commas, the relative word is required even when it is an object. The commas show that the clause merely adds information instead of identifying the noun; such a clause does not allow omission.

The cafe where we usually meet has closed for repairs.

Where explicitly identifies the meeting place. A version with a preposition is also possible: the café we usually meet at.

My cousin, who lives in Odesa, is visiting us in May.

The clause between commas only adds a detail; the relative word remains regardless of its role.

The colleague whose car we borrowed has moved to Kyiv.

Whose connects the colleague and the car; omitting it loses that relationship.

6. When retaining the word helps

Both versions are correct, but they are not always equally easy to read. If the relative clause's subject is long, that helps the reader immediately locate the clause's beginning.

The word is more often retained in an official letter, report, or instruction; it is commonly omitted in conversation and short messages. This concerns rhythm and clarity rather than correctness.

For people in the object role, who and that are both natural, and either can be omitted. Whom belongs to a markedly formal style and is unnecessary at this level.

The report that the finance department prepared last quarter is on the shared drive.

The relative clause's subject is long, so that makes the long sentence easier to read.

The report the finance department prepared last quarter is on the shared drive.

The same idea in a more compact form. It is correct, though a reader may need a moment longer to process it.

The person who I called yesterday has already replied.

Who is the object here, so it can be retained or omitted; that is also natural in this position.

7. How this works in everyday speech

Relative clauses without an object marker are very common in conversation. Look for a noun followed by a clause with its own subject: the book you read. Not every pair of adjacent nouns forms this construction.

When speaking, build the phrase in two steps: name the thing or person, then immediately add who did something involving them. No pause is needed between the parts, and you can leave out the relative word.

Questions work the same way. Clarifications such as the one you… commonly omit the relative word, providing a quick way to check exactly what someone means.

Is this the folder you printed for the meeting?

A clarification question: you follows folder directly, so the relative word is unnecessary.

I finally read the book you left on my desk.

A noun followed by a new subject, you: this is the structure that permits omission.

The person who answered the phone did not know.

The person did the answering, so who supplies the relative clause's subject and remains.

Common mistakes

Incorrect:The driver brings our bread arrives at five.

Correct:The driver who brings our bread arrives at five.

Who is the subject of brings and must remain. Without it, brings and arrives lack the required connection.

Incorrect:The machine prints the labels is broken.

Correct:The machine that prints the labels is broken.

The machine itself prints, so the relative word is the clause's subject and cannot be omitted. Which also works for the thing here.

Incorrect:The blanket Olena washed it last week smells of lavender.

Correct:The blanket Olena washed last week smells of lavender.

Blanket already identifies the object, so it inside the relative clause is redundant: the object position must remain empty.

Incorrect:My sister, I met at the station, works nearby.

Correct:My sister, who I met at the station, works nearby.

The clause between commas merely adds information about the sister; this type of clause requires a relative word even in the object role.

Incorrect:The pool we swim is closed in August.

Correct:The pool where we swim is closed in August.

Swim needs a locative connection to pool here, so where cannot simply be omitted under the who/which/that rule.

Incorrect:The excuse what he invented was not convincing.

Correct:The excuse he invented was not convincing.

In standard English, this relative clause modifying a named noun does not use what: that, which, or omission is possible here.

Sources