In linguistics

Linguistics

Linguistics is the scientific study of human language. Linguistics can be broadly broken into three categories or subfields of study: language form, language meaning, and language in context....

, an interrogative word is a function word

Function word

Function words are words that have little lexical meaning or have ambiguous meaning, but instead serve to express grammatical relationships with other words within a sentence, or specify the attitude or mood of the speaker...

 used for the item interrupted in an information statement. Interrogative words are sometimes called wh-words because most of English

English language

English is a West Germanic language that arose in the Anglo-Saxon kingdoms of England and spread into what was to become south-east Scotland under the influence of the Anglian medieval kingdom of Northumbria...

 interrogative words start with wh-. In English, they are used in question

Question

A question may be either a linguistic expression used to make a request for information, or else the request itself made by such an expression. This information may be provided with an answer....

s (Where is he going?) and interrogative content clauses (I wonder where he is going); their forms are also used as relative pronoun

Relative pronoun

A relative pronoun is a pronoun that marks a relative clause within a larger sentence. It is called a relative pronoun because it relates the relative clause to the noun that it modifies. In English, the relative pronouns are: who, whom, whose, whosever, whosesoever, which, and, in some...

s in certain relative clause

Relative clause

A relative clause is a subordinate clause that modifies a noun phrase, most commonly a noun. For example, the phrase "the man who wasn't there" contains the noun man, which is modified by the relative clause who wasn't there...

s (The country where he was born) and certain adverb clauses (I go where he goes). These uses are all found in various other languages as well.

Interrogative words in English include:

• interrogative determiner
  Determiner (class)
  A determiner is a noun-modifier that expresses the reference of a noun or noun-phrase in the context, rather than attributes expressed by adjectives...
  
  
  • which, what
  • whose (interrogative possessive determiner)
• interrogative pro-form
  Pro-form
  A pro-form is a type of function word or expression that stands in for another word, phrase, clause or sentence where the meaning is recoverable from the context...
  
  
  • interrogative pronoun
    Pronoun
    In linguistics and grammar, a pronoun is a pro-form that substitutes for a noun , such as, in English, the words it and he...
    
    
    • who, whom (personal)
    • what, which (impersonal)
  • interrogative pro-adverb
    Pro-form
    A pro-form is a type of function word or expression that stands in for another word, phrase, clause or sentence where the meaning is recoverable from the context...
    
    
    • where (location)
    • whence (source)
    • whither (goal)
    • when (time)
    • how (manner)
    • why, wherefore (reason)
    • whether (choice between alternatives)

A frequent class of interrogative words in several other languages is the interrogative pro-verb

Pro-verb

In grammar, a pro-verb is a word or phrase that stands in place of a verb . It does for a verb what the more widely known pronoun does for a noun. It, along with pronouns and some other word classes, form the general group of word classes pro-forms. It is a type of anaphora...

:

• Korean
  Korean language
  Korean is the official language of the country Korea, in both South and North. It is also one of the two official languages in the Yanbian Korean Autonomous Prefecture in People's Republic of China. There are about 78 million Korean speakers worldwide. In the 15th century, a national writing...
  
  : Nalssi-ga eotteoh-seumni-kka? (Hangul
  Hangul
  Hangul,Pronounced or ; Korean: 한글 Hangeul/Han'gŭl or 조선글 Chosŏn'gŭl/Joseongeul the Korean alphabet, is the native alphabet of the Korean language. It is a separate script from Hanja, the logographic Chinese characters which are also sometimes used to write Korean...
  
  : 날씨가 어떻습니까?) Weather-nominative be_how-politeness fifth level-interrogative suffix "How's the weather?"

• Mongolian
  Mongolian language
  The Mongolian language is the official language of Mongolia and the best-known member of the Mongolic language family. The number of speakers across all its dialects may be 5.2 million, including the vast majority of the residents of Mongolia and many of the Mongolian residents of the Inner...
  
  : Chi yaa-vch jaahan huuhed bish gej bi bod-jii-ne You do_what-concessive small child not that I think-progressive-nonpast "Whatever you do, I think you’re not a small child." (Example taken from an Internet forum)

See also

• Five Ws
  Five Ws
  In journalism, the Five Ws is a concept in news style, research, and in police investigations that are regarded as basics in information-gathering. It is a formula for getting the "full" story on something...
  
  
• Sentence function
  Sentence function
  In linguistics, sentence function refers to a speaker's purpose in uttering a specific sentence, phrase, or clause. Whether a listener is present or not is sometimes irrelevant. It answers the question: "Why has this been said?" The four basic sentence functions in the world's languages include the...