Expressing certainty or uncertainty

Question 1

Check certainty of speaker (neutral)

Answer 1

Are you sure?

Is that really true?

Can you be absolutely certain?

Question 2

Check certainty of speaker (informal)

Answer 2

Are you pulling my leg?

Question 3

Express degrees of certainty (neutral)

Answer 3

We’ll see

I don’t know for sure

I’m not well informed

That may be true

Could be

Possibly

I’m afraid it’s true

It’s a fact

Without a doubt

I’m sure that

Question 4

Express degree of certainty (informal)

Answer 4

It’s a (dead) cert

Question 5

Ask if someone remembers/knows/ is aware (neutral)

Answer 5

Do you remember…

Where you aware of this?

Did they tell you that?

Question 6

Ask if someone remembers/knows/ is aware (formal)

Answer 6

Are you acquainted with…?

Question 7

Ask if someone remembers/knows/ is aware (informal)

Answer 7

Are you clued up on…

How well up are you on…

Are you in on this?

Question 8

Say you remeber/know/are aware (neutral)

Answer 8

I’m familiar with

I’ve been informed

That rings a bell

Question 9

Say you remeber/know/are aware (informal)

Answer 9

I’m well up on

I’m in on this

Question 10

Say you don’t remember/know/ are aware (neutral)

Answer 10

I don’t know anything about…

It’s a closed book to me

I can’t recall

Question 11

Say you don’t remember/know/ are aware (informal)

Answer 11

How should I know?

Don’t ask me

Search me