That vs What

When to use each in English, with meaning, register, and examples.

That

High-frequency chunk A1 determiner

What

High-frequency chunk A1

	That	What
Pronunciation	🇬🇧 /["/ðæt/","/ðəʊz/"]/ 🇺🇸 /["/ðæt/","/ðəʊz/"]/	🇬🇧 /["/wɒt/"]/ 🇺🇸 /["/wʌt/"]/
Meaning	used to refer to a specific thing or person	Used to ask for information about something.
Example	Look at that man over there.	What is your name?
Register	Neutral	Neutral
How common	High-frequency chunk	High-frequency chunk
CEFR level	A1	A1
Part of speech	determiner
Collocations	that is, that way, that means, not that, that much	what time, what if, what about
Antonyms	this	that, nothing
Common mistakes	Confusing 'that' with 'which' in restrictive vs non-restrictive clauses., Using 'that' when the antecedent is a person (use 'who')., Overusing 'that' in sentences, which can make them awkward.	'What' is sometimes confused with 'which' when choosing from specific options., Learners may forget to use a subject after 'what'., Using 'what' to ask about time, when 'when' should be used.
Usage notes	Used to refer to something already mentioned or known. In spoken English, it's often used informally. Be careful not to use it in overly formal writing where specificity is needed.	Used to ask questions in a variety of situations. Avoid in very formal contexts; in those cases, use 'that which' or 'which one'.

Frequently asked questions: That vs What

What's the difference between That and What?

That: used to refer to a specific thing or person What: Used to ask for information about something.

Are That and What the same CEFR level?

That: A1, What: A1 on the CEFR scale.

Can you show an example of each?

That: Look at that man over there. What: What is your name?

Can I use That and What interchangeably?

Not always. That and What are related and overlap in some contexts, but they differ in register, how common they are, and usage, so swapping one for another can change the meaning or tone. Check the differences above before substituting.