In most varieties of English, the wh- words are also used as relative pronouns.
Wh-words are also used to begin wh-clauses.
- Echo Question
- Free (Nominal) Relative Clause
- Journalists' Questions
- Relative Adverb
- Relative Clause
- Who, Which, and That
- Who and Whom
Examples and Observations:
- Wh- words are unique among flag words in that they belong to different parts of speech. Here are the most common wh- words classified by their parts of speech. Notice that many of the wh- words can be compounded with -ever.
NounsThe last two words on the list, how and however, do not actually begin with wh-. We will treat them as honorary members of the wh- family."
(Mark Lester and Larry Beason, The McGraw-Hill Handbook of English Grammar and Usage. McGraw-Hill, 2005)
- wh-ever word
"A member of a class of words which resemble wh- words, from which they are derived by the addition of the suffix -ever: whoever, whichever, wherever, whenever, however and so on. wh-ever words begin nominal relative clauses and universal conditional clauses: Wherever you go, you'll have a ball."
(Geoffrey N. Leech, A Glossary of English Grammar. Edinburgh Univ. Press, 2006)
- Wh- Words in Noun Clauses
"Inside the noun clause, the wh- words that are nouns can play all four noun roles of subject, object of verb, object of preposition, and predicate nominative. The wh- words that are adverbs can play the standard adverb roles of denoting time, place, manner, and reason. In the following examples, note that all of the noun clauses play the same external role of subject of the verb in the main sentence:
Wh- words used as nouns inside wh- clausesIt is important to understand that noun clauses beginning with wh- words that are adverbs are just as much noun clauses as noun clauses beginning with wh- words that are nouns."
Subject: Whoever finishes first wins the prize.
Object of verb: Whatever I said must have been a mistake.
Object of preposition: What they agreed to is OK with me.
Predicate nominative: Who they were is still unknown.
Wh- words used as adverbs inside wh- clauses
Adverb of time: When you called was not a good time for me.
Adverb of place: Where you work is very important.
Adverb of manner: How you use your leisure time tells a lot about you.
Adverb of reason: Why they said that remains a complete mystery to us.
(Mark Lester, McGraw-Hill's Essential ESL Grammar. McGraw-Hill, 2008)
- Wh- Movement
"From the earliest days, transformational grammarians postulated that a wh- interrogative sentence is derived by a movement rule from a deep structure resembling that of the corresponding declarative. So, for example, and disregarding the inversion and the appearance of a form of do, a sentence like What did Bertie give -- to Catherine? would be derived from a deep structure of the form Bertie gave wh- to Catherine (the dash in the derived sentence indicates the site from which the wh- word has been extracted). Wh- movement can also extract wh- words from within embedded sentences, and apparently from an unlimited depth: What did Albert say Bertie gave -- to Catherine?, What did Zeno declare that Albert had said that Bertie gave -- to Catherine?, and so forth. The rule is, however, not entirely unconstrained. For example, if the constituent sentence is itself interrogative, then extraction cannot take place: Albert asked whether Bertie gave a book to Catherine, but not *What did Albert ask whether Bertie gave -- to Catherine?"
(E. Keith Brown, "Generative Grammar." The Linguistics Encyclopedia, 2nd ed., ed. by Kirsten Malmkjaer. Routledge, 2002)