Who vs That: People, Clause Type, and Omission

Quick Answer

Use who for people in both defining and non-defining relative clauses: The teacher who inspired me retired. Ms. Chen, who inspired me, retired.

That can replace who or whom for people in a defining relative clause, especially in informal use: The teacher that inspired me retired. It cannot introduce a non-defining clause: write Ms. Chen, who inspired me, not Ms. Chen, that inspired me.

Separate preference from prohibition

Choosing who for a person is a clear general default. Calling every defining that with a human antecedent ungrammatical is inaccurate. By contrast, excluding that from a comma-delimited non-defining clause is a structural rule.

Connector	Typical referent	Defining clause	Non-defining clause	Register note
who	people; sometimes pet animals	yes	yes	available across clause types
that	people, animals, and things	yes	no	Cambridge labels the relative use informal

The Clause Type Decides More Than the Antecedent

A defining relative clause supplies information needed to identify the person or group. It normally appears without surrounding commas. A non-defining clause adds information about someone already identified and is set off with commas.

Sentence	Reference meaning	Available form
The applicants who submitted portfolios advanced.	The clause identifies a subset of applicants.	who; that is also grammatical in this defining clause.
The applicants that submitted portfolios advanced.	The same subset meaning, with Cambridge's more informal relative form.	that is allowed because the clause is defining.
Leila, who submitted a portfolio, advanced.	Leila is already identified; the clause adds information.	who, not that.

Commas are not decoration here. They signal a different relationship between the clause and its antecedent. Do not change who to that until you have decided whether the clause identifies the referent or merely supplements it.

Subject and Object Roles Control Omission

The relative pronoun has a grammatical job inside its own clause. Rebuild that clause as a plain sentence to locate the gap.

Relative phrase	Plain reconstruction	Role	May the connector disappear?
the consultant who called	the consultant called	subject of called	no
the consultant that called	the consultant called	subject of called	no
the consultant who we hired	we hired the consultant	object of hired	yes, in this defining clause
the consultant that we hired	we hired the consultant	object of hired	yes, in this defining clause

The omission rule does not belong uniquely to that. Cambridge records omission for object relative pronouns in defining clauses, including a human example with whom, who, or that. Keep the relative pronoun when it supplies the subject, and keep every connector in a non-defining clause.

People, Organizations, and Pet Animals Need Different Questions

A named or identified person

Defining:

The editor who approved the cover will call.

Non-defining:

Rosa, who approved the cover, will call.

Who works in both clause types and makes the human referent explicit.

An organization as an entity

Entity:

The agency that issued the notice closed.

Named people:

The agency staff who issued the notice responded.

The first antecedent denotes the organization as an entity; the second explicitly denotes people. If a collective noun makes that distinction unclear, name the members or rewrite the entity.

A pet animal

Cambridge-supported option:

That is the dog who avoids me.

Cambridge includes pet animals among possible referents for who. Do not turn “who only for humans” into an absolute.

Four Repairs with Four Different Causes

Non-defining that

Wrong clause type:

My mentor, that lives nearby, reviews my drafts.

Supplementary person clause:

My mentor, who lives nearby, reviews my drafts.

The commas mark a non-defining clause. Cambridge excludes that from this clause type.

Thing with who

Referent mismatch:

The laptop who failed was under warranty.

Thing in a defining clause:

The laptop that failed was under warranty.

Cambridge lists who for people and sometimes pet animals; that can refer to things in a defining clause.

Missing subject connector

Subject gap:

The analyst prepared the forecast will present it.

Subject restored:

The analyst who prepared the forecast will present it.

Who is the subject of prepared, so it cannot be omitted.

Unnecessary object connector

Connector kept:

The analyst who we hired will present.

Connector omitted:

The analyst we hired will present.

Both are available in this defining object clause. Omission is a choice, not a mandatory simplification.

Test Referent, Clause Type, and Role

1. Priya, ___ designed the system, will demonstrate it.

2. The people ___ registered may enter. Which is grammatical?

3. The device ___ failed has been replaced.

4. In “the editor who called,” may who be omitted?

5. In “the editor who we hired,” may who be omitted?

Live Check: One Valid Variant and Two Missed Boundaries

On July 16, 2026, Grammarlyzer returned no issues for the exact defining person clause below or its who variant. It also returned no issues for My mentor, that lives nearby, reviews my drafts. and The laptop who failed was under warranty., as well as their manual repairs.

Exact tested defining-clause seed:

Also grammatical with a human-specific connector: The teacher who inspired me retired.

The six submissions document two accepted defining variants, two contextual false negatives, and two accepted repairs. They do not establish behavior for every antecedent, clause type, comma pattern, omission, or register. Use the checker as a second view, not as the clause-type decision.

Frequently Asked Questions

Is that grammatically wrong for people?

No. Cambridge records that as an informal alternative to who or whom for people in defining relative clauses. The people who called and the people that called can both be grammatical. Who is available in both defining and non-defining clauses, while that is limited to defining clauses.

Can that introduce a non-defining clause about a person?

No. A non-defining relative clause adds supplementary information about an already identified person and uses commas. Cambridge says that does not introduce this clause type, so write My mentor, who lives nearby, not My mentor, that lives nearby.

Should an organization take who or that?

When the antecedent denotes the organization as an entity, that or which is the clearer category match: the agency that issued the notice. When the antecedent names people or members, who fits: the staff members who issued the notice. Rewrite a vague collective noun if the entity-versus-members meaning is unclear.

When can who or that be omitted?

A relative pronoun can often be omitted when it is the object in a defining clause: the consultant who or that we hired can become the consultant we hired. Keep it when it is the subject, as in the consultant who called, and keep the connector in a non-defining clause.

What did Grammarlyzer report for the exact who and that tests?

On July 16, 2026, Grammarlyzer returned no issues for The teacher that inspired me retired, My mentor, that lives nearby, reviews my drafts, or The laptop who failed was under warranty. It also returned no issues for the corresponding who, who, and that revisions. The results document two grammatical variants and two contextual false negatives; they do not show that every tested seed is suitable for edited prose.

What the Direct Sources Support

Cambridge Grammar: relative pronouns — referent and clause-type ranges for who and that, object omission, pet animals, and human examples with who, whom, or that.
Cambridge Grammar: that — that introduces defining relative clauses, can replace who, whom, or which for people, animals, and things, and is more informal than who or which.
Cambridge Grammar: defining and non-defining relative clauses — essential versus supplementary information, comma behavior, informal defining that for people, required non-defining connectors, and the exclusion of that.
Cambridge Grammar: who and whom — who in relative clauses about people and whom as a formal object form.

These sources support grammar and register labels, not claims about respect, warmth, reader reaction, editor behavior, or error frequency. Those unsupported claims have been removed.

A Five-Step Who-or-That Audit

Underline the antecedent. Is it a person, pet animal, organization as an entity, other animal, or thing?
Decide the clause type. Does the clause identify the referent, or add supplementary information about someone already identified?
Find the gap. Rebuild the relative clause to determine whether the connector is its subject or object.
Choose within the real options. Use who as the broad human default; allow informal defining that; exclude that from non-defining clauses.
Test omission and clarity. Omit only an object connector in a defining clause, and rewrite vague collective reference rather than guessing.

What This Pair Guide Adds to the Relative-Clause Cluster

The relative clauses guide maps all major connectors, clause types, gap roles, prepositions, and punctuation. This narrower page resolves the common overstatement that that cannot refer to people, contrasts a style default with a structural prohibition, and documents six exact checker submissions.

The who versus whom guide focuses on subject and object case, while which versus that focuses on connectors for things. The pronoun foundation introduces pronoun role and reference across categories.

Decide the Clause Before Enforcing the Default

Use the checker for sentence-level feedback, then verify the antecedent, clause type, and connector role yourself.

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