‘What' vs. 'Which': What's the Difference?

Do you need to know the difference between ‘what' vs. 'which?' If so, you're in luck!

Here is the quick answer:

• 'What' is an interrogative adjective, pronoun, and adverb that expresses interest in the identifying features of a person, thing, or material.
• 'Which' is an interrogative adjective, pronoun, and conjunction used to ask someone about their selection, choice, or preference out of a selection.

To truly understand the meanings and how to use these essential English words, we need to take a deeper dive into the meanings and usages. But that is exactly what I am going to do in this guide. So, keep reading!

What's the Difference Between 'What' vs. 'Which?'

'What' and 'which' are two commonly used English words. So, it is important to know the difference between them.

• The first is an interrogative adjective, pronoun, and adverb,
• while the latter is an interrogative adjective, pronoun, and conjunction.

So, you can use 'which' to connect two phrases.

When to Use 'What vs. 'Which?'

In some cases, you may be able to use either term. However, in other situations, only one of these is appropriate.

So, how do you know which to use?

Here are some tips: 

• Use 'what' as an interrogative adjective to ask for someone's choice.

For example, you could say:

What is your favorite ice cream flavor? Mine is Ben and Jerry's Chunky Monkey.

• Use 'what' as a pronoun to ask the 'what' of a situation.

For example, an investigator might say:

We know the what and where, but we are still trying to prove who committed the crime and why. 

• Use 'what' as an adverb to ask what something is or does.

For example, you might say:

What does your dad think of you taking the job in New York? I hope he is being supportive. 

• Use 'which' as an interrogative adjective to ask what option someone likes out of a set of choices.

For example, you could say:

Which of the cars that we test-drove do you want to buy? 

• Use 'which' as a pronoun to determine someone's preference.

For example, I might say:

Do you know which team member is the best? 

• Use 'which' as a conjunction to join independent phrases.

For example, you might say:

We went to the hotel on the hill, which was her favorite place to eat with her dad. 

Definition of 'What': What Does 'What' Mean?

According to the Merriam-Webster Dictionary, the definition of  'what' is:

• An interrogative inquiry about the nature of something

It can also mean:

• A request for someone to repeat something
• An interrogative to inquire about the state, nature, position, or other details
• An interrogative to inquire about the identity
• An expression of surprise or excitement
• An expression directing attention to a thought
• A reference to a statement that follows
• A remark drawing attention to shockingly good or bad qualities

Phrases Containing 'What'

• Who, what, when, where, why
• What a day!
• What did you say?
• What time?
• What a difference!
• What is your name?
• What is the date?
• What beauty!
• What now?
• What do you want?

Definition of 'Which': What Does 'Which' Mean?

The same dictionary defines 'which' as:

• An interrogative used to request a choice out of a selection of options

It can also mean:

• A term used to introduce relative clauses or modify nouns
• Used to refer back to a person, idea, animal, inanimate object, or action
• A reference to a person
• A term used to introduce background information
• An interrogative term to ask for a selection or relative information

Phrases Containing 'Which'

• Which one?
• In which case
• Which is which
• Which way?
• Which is why
• Which is due to
• Which would you like?
• Which is best?

Pronunciation: How Do You Pronounce 'What' vs. 'Which?'

You know how to use 'what' and 'which.' Both terms are commonly used in English. Whether you are a native speaker trying to improve your writing or an English language learner, it is essential to know how to pronounce them.

So, here is a pronunciation guide for 'what' vs. 'which':

• Use this phonetic spelling to pronounce 'what':

wät

• Use this phonetic spelling to pronounce 'which':

wich

Sample Sentences Using 'What' vs. 'Which'

Before you go, here are some sample sentences using 'what' vs. 'which.' Read them to ensure you know how to use these words in different contexts.

What

• What do you want to do tonight? I was thinking that we could go to a movie and dinner, but we can do something else if you want.
• Will you tell me what you were thinking when you got on that wild horse? That was dangerous and reckless.
• What time will you arrive? I need a general idea so I can make sure I am back from my afternoon meeting.
• If you knew what I went through to get here!

Which

• Which house did you like best? I liked the house that was on the left, which had pink and white colored flowers in the front.
• Do you know which classes you will take during the Fall semester? I am still working on my core classes, so I can't take any electives.
• The executives went to a retreat, which the company paid for each year.
• Which part do you not understand?

Final Advice on the Difference Between 'What' vs. 'Which'

Knowing the difference between 'what' vs. 'which' is essential for all English speakers and writers. So, here is a quick recap: 

• 'What' is a pronoun, adverb, and adjective used as an interrogative term to figure out someone's preference.
• 'What' is also used as an exclamatory phrase in response to something extremely positive or negative.
• 'Which' is an adjective and pronoun used to ask for someone's choice out of a selection. 
• 'Which' is also a conjunction used to combine independent phrases. 

If you ever mix these terms up in the future, you can always come back to this page to review this lesson. You can also learn about many other commonly misused terms in our confusing words section. Each one gives definitions, usage tips, pronunciations, and examples. So, they are an excellent way to expand your vocabulary and improve your grammar.