Can who appear in a statement?

Yes. Relative clauses and embedded interrogatives can contain who inside a larger declarative sentence.

Is which always a pronoun?

No. It can stand alone in a pronominal use or accompany a noun as a determiner, depending on context and analysis.

AI Glossary / Natural language and speech / Beginner

Wh-pronoun

Definition

Definition: A wh-pronoun is a pronoun from the family of forms such as who, whom, what and which that can be used in questions and related constructions. For example, who stands for an unknown person in “Who approved the request?” Similar forms also occur in relative clauses.

What it means

What it means: The label refers to grammatical behavior, not just the letters w and h. Not every word beginning with wh is a pronoun. Where and when commonly function as interrogative or relative adverbs, while which in “which file” can be analyzed as a determiner accompanying a noun.
A wh-pronoun can occupy different roles within its clause, such as subject or object. Its presence alone does not prove that the whole sentence is a direct question. “I know who approved it” contains an embedded interrogative, while “the person who approved it” contains a relative clause. Those constructions need different interpretation.

How it works

How it works: A parser identifies the pronoun's category and its role in the surrounding structure. In a direct English question, a wh-expression often appears near the beginning, but the grammatical role it represents may correspond to a position elsewhere in the clause. In “Whom did Nora contact?”, whom is associated with the object of contact.
Annotation schemes differ in detail. Universal Dependencies distinguishes interrogative and relative values through its PronType feature, which also applies to some determiners and adverbs. A system should therefore inspect both part of speech and constructional features rather than treating every wh-form as one undifferentiated question marker.

Three practical examples

Three practical examples:
1. A question-answering system reads “Who approved the order?” and seeks an answer identifying the relevant approver. Recognizing who helps identify the requested participant, but the system still needs evidence about the order.
2. A document parser reads “The analyst who checked the totals signed the form.” The relative pronoun links a clause to analyst; it is not asking the reader to supply a name.
3. A help assistant distinguishes “Which failed?” from “Which sensor failed?” In the first, which can stand on its own as a pronoun; in the second, it accompanies sensor as a determiner under the stated analysis. The requested information depends on the larger phrase and context.

Think of it this way

Think of it: In a question, a wh-pronoun resembles a labeled blank in a form, indicating the kind of missing participant to identify. In a relative clause, a similar form can instead connect a description to an already mentioned item. The analogy is limited because grammatical role, discourse context and available alternatives cannot always be reduced to a single fixed form field.

Worked example

Worked example: Classify the highlighted form in three invented sentences. A: “Who repaired the unit?” B: “The technician who repaired the unit called.” C: “Which unit failed?” Under a conventional analysis, A contains an interrogative pronoun, B a relative pronoun, and C an interrogative determiner accompanying unit.
There are three wh-form occurrences but only two pronoun occurrences in this sample. Only A is a direct question whose highlighted form is itself a pronoun; C is a direct question headed by a larger wh noun phrase. B is a statement containing a relative clause.
A rule that marks every wh-form as both a pronoun and a direct-question trigger makes errors of two kinds: category on C and sentence function on B. The exercise shows why spelling, word class and clause type need separate labels. These are illustrative annotations under a stated convention, not a claim that all grammatical frameworks use identical terminology.

Illustrative case study

Illustrative case study: Fictional Ash Help routes customer messages containing who to a “question about a person” queue. It incorrectly routes statements such as “The courier who delivered the parcel left a note.” The word who is present, but the customer has not necessarily asked a question.
The team adds clause-level analysis and tests direct questions, embedded questions and relative clauses separately. It also checks whether the message contains a request expressed without a wh-form. This fictional case illustrates a classification shortcut that fails. It does not claim that parsing alone identifies every customer's intent or that grammatical questions always request information literally.

Common misconceptions and mistakes

Common misconceptions and mistakes: Wh-pronoun is not a synonym for every wh-word. A question mark is not required for an embedded interrogative, and a wh-form can occur in a declarative sentence. Who and whom are not simply interchangeable in every register or construction, although actual usage varies. A relative pronoun is not merely an unanswered question. Finally, recognizing the grammatical role of an unknown participant does not identify the participant or prove the presupposed event happened.

Business use

Business use: Wh-pronoun analysis can support question answering, document parsing and message routing. Build tests around clause type and grammatical role rather than a list of trigger spellings. Preserve context for which and what, since their intended domain may be established earlier in a conversation. Distinguish a request for a person, an item or a choice from a relative-clause description. Before generating an answer, verify the underlying facts instead of treating the question's wording as evidence that its premise is true.

Check your understanding

Check your understanding: In “The engineer who reviewed the design is away,” does who make the whole sentence a question?

Answer: No. It introduces a relative clause modifying engineer under the stated analysis. The main sentence makes a statement. A routing rule based only on the presence of who would miss that distinction.

Related terms

Pronoun
Determiner
Part of speech
interrogative
relative clause
wh-question
embedded question
subject
object

Learn next

compare who in a direct question, an embedded question and a relative clause. Mark the boundaries of each clause and the pronoun's role within it. Then compare which used alone with which followed by a noun, keeping category and sentence function separate.

Pronoun

Sources

Sources: Jurafsky and Martin, Speech and Language Processing, Chapter 18, pronouns and wh-forms: https://web.stanford.edu/~jurafsky/slp3/18.pdf . Universal Dependencies, PronType documentation, interrogative and relative features across pronouns, determiners and adverbs: https://universaldependencies.org/u/feat/PronType.html . The three-sentence classification and Ash Help case are original illustrations under explicitly stated grammatical conventions.

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