What part of speech is "when"?

To determine the part of speech of "when",we need to know the types of parts of speech.Remember that there are eight types of parts of speech in English language.


The eight types of  parts of speech are noun,pronoun,verb,adverb,preposition, conjunction and interjection.Remember that determiners are a special type of adjective.

To find out the part of  speech of "when",we need to  remember that a single word in different sentences can functions as different parts of speech.



Now analyse the following example:

●When will he return?


Explain:Here "when"is modifying the verb "return".We know that only adverb can modify a verb.So the part of speech of when is an adverb here.Observe the following example:


●He will return in the morning.

●When will he return?


Now read the explanation below:


●He will return in the morning.


We know that return is here an intransitive verb.So "return" does not have any object here.A object sits after a verb without any preposition before it.


●He will return in the morning.

Sometimes a noun becomes an adverb with the help of a preposition.To be a preposition,a part of speech must have a noun or noun phrase after it.

●He will return in the morning.

Here "the morning" is a noun phrase and functioning  as the object of "in"."In the morning" is a prepositional phrase from the structural side but it is functioning as an adverb here(when return=in the morning)


●He will return in the morning.

●When will he return?

●When=in the morning







Now consider the following example:


●She went fishing when she was a girl.

Explanation:


Structure of a clause:

●Sub.+Finite verb+Extension.

●Clause +Conjunction+Clause

A conjunction can join two clauses.

●She went fishing when she was a girl.

●Clause=She went fishing


 ●Clause=she was a girl.

◆Clause +when+clause


●She went fishing when she was a girl.

Here "when" is connecting two clauses together.So,the part of speech of" when" is a conjunction here.


Now consider the following example:


●Liza is a beautiful girl.She can dance.


Here "she"is a pronoun because "she" is  replacing the word "Liza" which is a noun.We know that a pronoun can replace a noun.

Similarly,

●He left on Sunday,since when we have heard nothing.


Here,"Sunday" is a object of the preposition "on".Here"Sunday"is a noun.

●He left on Sunday,since when we have heard nothing.


In this sentence "when"is a object of the preposition since.Here "when" is replacing the noun"Sunday".We know that only a pronoun can replace a noun.That is why "when" is a pronoun here.

●(When as pronoun means=Which time)


Now analyse the following example:


Have You decided the where and when?

Here"when" is used as the object of the verb " decided".We know that an object may be a noun or pronoun.


Structure of Noun Phrase:
●Determiner+Noun

=the +when

=the+where


●Have You decided the where and when?

Here the part of speech of when is a noun.

(Meaning=When=The time or date)

Conclusion:We are getting four  parts of speech for "when":an adverb, a conjunction , a pronoun and a noun)