The difference between: what and that

This is something that I often hear native English speakers get wrong!

Follow these tips to work out whether to use what or that.

That is a thing

That refers to a specific thing "I like that dress you are wearing." - that refers to the dress.

What is a question

What is used to ask a question "What are you going to wear to the party tonight?" - what asks for more information, in this case about your outfit!

• "I like that car."

In this sentence 'that' refers to the specific car.

• "What car do you have?"

'What', in this case, asks a question about your car.

What always wants to find out more information.

I often hear "I like the car what you have." This is not correct.

In this sentence 'the' is used to refer to a specific object (the car) but 'what' should be replaced by 'that' because you are not asking a question.

This sentence is not a question so 'what' shouldn't be used.

'That' should be used because it talks about a specific car

• "I like the car that you have."

An even better sentence would be "I like your car."

• "I have finished reading the book that I bought last week!"

In this sentence 'that' gives us very specific information about the book - it was bought last week.

• "What books did you buy last week?"

'What' asks for more information about the books that our friend bought.

"I've finished reading the book what I bought last week." is not correct because this is not a question. We use 'what' to ask a question and we use 'that' to refer to something specific - the book that I bought last week.

• "I've finished reading the book that I bought last week."

Remember - that is a thing and what is a question.

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