The word “when” has multiple functions. It can be used as an adverb, conjunction,  pronoun, and noun.

 

1. Adverb

This word is categorized as an adverb because it modifies a verb, and adjective, or another adverb by indicating the time. For example, in the sentence below:

Sunday is the day when I get my hair done.

The word “when” is used to denote the time (Sunday) when the verb is performed.

Definition:

a. at what time

• Example:
• When did you last see Carlo?

 

2. Conjunction

In some cases, it is also considered as a conjunction because it can join two clauses or phrases together by suggesting the time. Furthermore, it can also substitute the words “whereas” or “although.” In the sample sentence below:

Raise your hand when you’re finished.

The word “when” connects “raise your hand” with “you’re finished.”

Definition:

a. at or during the time that.

• Example:
• I loved math when I was in middle school.

 

b. after which; and just then

• Example:
• She had just drifted off to sleep when the doorbell buzzed.

 

c. although; whereas

• Example:
• I’m saying it now, when I should have told you long ago.

 

3. Pronoun

Other times, the word “when” is classified under pronouns if it is used to represent an unknown or unspecified time. For instance, in the example:

You need the report by when?

The word “when” is considered as a pronoun because it represents the unknown time when the report is needed.

Definition:

a. what or which time

• Example:
• I have lived here, since when I was born.

 

4. Noun

Sometimes, the word “when” is also used as a noun which refers to the time when something happened or is done. For example, in this sentence:

He is troubled by the how and when of life.

“When” is the noun, it is a particular period of life and is the doer of an action- it “troubled” the subject “He.”

Definition:

a. the time in which something is done or comes about

• Example:
• The confusion is over the when of the statement.