I have no idea about where she is. Vs I have no idea where she is .

He really needs to learn a lot of things. Vs He really needs to learn about a lot of things.

I don't know where she lives. Vs I don't know about where she lives.

I literally want to know how they came here. Vs I literally want to know about how they came here.

Could anyone please explain to me, when to use about and when not to? When is the use of About necessary and when it is futile ?

  • Why do you think there is any difference?
    – user3169
    Commented Jun 10, 2018 at 22:34

1 Answer 1


We use about after know when we mean more information on this subject.

We omit about when we are referring to one or two facts rather than information in general.

Typical examples would be:

I have no idea where she is. (No about)

I am fascinated by astronomy. I want to know more about it.

He needs to learn his Latin conjugations. (No about)

He needs to learn about Roman culture.

I want to know how they caught the murderer. (No about)

I want to know about the methods they used to catch the murderer.

I don't know him well. (No about)

I don't know much about him.

So the more general and comprehensive the information that is being sought, the more likely it is that you will use about.

There are also examples where about is optional, depending on the nuance and what you want to emphasise.

You might say either:

I don't know Peter

meaning that you haven't met him or are not acquainted with him,

or, if you were considering who might be a suitable candidate for a position:

I don't know about Peter

suggesting that you doubt whether Peter would be suitable.

I didn't know this (that your aunt was ill)

meaning you were not acquainted with this fact, and

I didn't know about this (that the wedding had been called off)

suggesting that you were acting in ignorance of some significant development.

But in both these last examples about is optional.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .