Interrogative Adverbs

The interrogative adverbs are "why," "where," "when," and "how." They are used to ask questions. For example (interrogative adverbs shaded):

Why is the garden in such a mess?

Where is your sister?

When are you going to grow up?

How can you eat a freezer full of pizzas in one evening?

Note: When an interrogative adverb starts a question, the second word is the verb.

Different Types of Interrogative Adverb

Interrogative adverbs are used to ask different types of questions. For example, "when" is used to ask about time-related matters, "where" is used to ask about place-related matters, and "why" is used to ask about reasons. The quirky one is "how," which can be used to ask about matters related to manner (e.g., How quickly?), time (e.g., How soon?), quantity (e.g., How many?), amount (e.g., How much?), and dMore about Interrogative Adverbs

The answer to a question posed with an interrogative adverb will always be something functioning as an adverb (i.e., a single-word adverb, an adverbial phrase, or an adverbial clause). For example:

When should I remove the tin foil from the muffins?

Single-word adverb. Immediately

An adverbial phrase. As soon as possible

An adverbial clause. When the alarm sound

Interrogative adverbs contrast with interrogative determiners ("what," "which," "whose") and interrogative pronouns ("what," "which," "who," "whom," and "whose"). Interrogative determiners modify nouns (e.g., Which muffin is best?), while interrogative pronouns stand alone (e.g., Which is best?). The answer to a question posed by an interrogative determiner or an interrogative pronoun will always be something functioning as a noun.

Interrogative Adverbs of Time

When an interrogative adverb is used to ask about a time-related matter, it is known as an interrogative adverb of time. Typically, the interrogative adverb will be "when," but "how" is also used to ask time-related questions. For example:

When will this film end?

When was the last time you found something you wish you hadn't?

How long is left until the end of the film?

How often do you come to the cinema?

Interrogative adverbs of Place

The interrogative adverb "where" is used to ask about a place. For example:

Where do crayfish spend their winters?

Where is the line between soup and cereal?

Interrogative Adverbs of Reason

The interrogative adverb "why" is used to ask about a reason. For example:

Why are you watching this film again?

Why do they call it rush hour when nothing moves? (Actor Robin Williams)

Interrogative Adverbs of Manner

The interrogative adverb "how" is used to ask about manner (i.e., the manner in which the verb occurs). For example:

How quickly can you get home?

Interrogative Adverbs of Amount, Quantity, and Degree

The interrogative adverb "how" is used to ask for amounts, quantities, and degrees. For example:

How much coke have you got left?

How many sweets have you eaten?

How complicated can this get?

Interrogative Adverbs Can Also Be Used in Indirect Questions

Interrogative adverbs are also used in indirect questions.

An indirect question is a question embedded inside a statement (i.e., a declarative sentence ending typically in a period (full stop) or another question (i.e., an interrogative sentence ending in a question mark).

Examples (interrogative adverb shaded):

She asked where you were going.

(This is an example of an interrogative adverb being used in an indirection question in a declarative sentence.)

Did she ask where you were going?

(This is an example of an interrogative adverb being used in an indirection question in a interrogative sentence, i.e., another question.)

Word Order in an Indirect Question

The word order in an indirect question is the same as for a declarative sentence and not an interrogative sentence. For example:

Are you happy?

(This is an interrogative sentence. The word order is verb ("Are") then subject ("you").)

You are happy.

(This is a declarative sentence. The word order is subject ("You") then verb ("are").)

She is asking if you are happy.

(This is an indirect question. The word order is the same as for a declarative sentence, i.e., a statement.)

Interrogative Adverbs Can Also Be Used at the Head of Noun Clauses

A noun clause is a clause that plays the role of a noun.

Often, a noun clause will start with one of the so-called "wh"-words (e.g., "what," "who," "which," "when," "where," "why"), a group which includes the interrogative adverbs. For example:

I know where it happened.

I know when it happened.

I know why it happened.

Why Should I Care about Interrogative Adverbs?

Generally, the interrogative adverbs do not cause many writing issues for native English speakers, who can use them without giving the grammar a second thought. However, if you're learning or teaching English, then it is important to understand how interrogative adverbs are used to form direct questions and indirect questions, particularly the word order of those sentence structures.

With indirect questions in mind, here is one mistake related to interrogative adverbs that native English speakers regularly make.

(Common Mistake) Don't use a question mark after a non-question.

Don't forget that an indirect question can be embedded in a statement. When this happens, don't use a question mark.

I wonder when she will fly again?

The boss wants to know where yesterday's PowerPoint slides are?

(These are not questions but statements. They should end in periods (full stops).)

An indirect question is a direct question embedded inside a statement or another question. Here, the embedded direct questions are "When will she fly again?" and "Where are yesterday's PowerPoint slides?".