Wh-words are what, when, where, who, which, why and how.

We use clauses with a wh- word:

  • In wh-questions (see Questions and Negatives):

What are you doing?
Who ate all the pies?
Why did you do that?

  • after verbs of thinking:

know - understand - suppose - remember - forget - wonder

I know where you live.
She couldn’t remember who he was.
John wondered what was going to happen next.

NOTE: We also use clauses with if

I wonder if we’ll see Peter.
She couldn’t remember if she had posted the letter.

  •  after verbs of saying:

ask - say - admit - argue - reply - agree - mention - explain - suggest

I asked what she wanted.
He tried to explain how the accident had happened.
She wouldn’t admit what she had done.
Did he say when he would come?

tell and some other verbs of saying must always have a direct object (see clauses, sentences and phrases):

tell - remind

We tried to tell them what they should do.
She reminded me where I had left the car.

  • after some verbs of thinking and saying we use wh-words and the to-infinitive:

We didn’t know what to do.
We will ask when to set off.
Nobody told me what to do.
Can anyone suggest where to go for lunch?

NOTE: We use the to-infinitive:

-- When the subject of the to-infinitive is the same as the subject of the main verb:

He didn’t know what to do >>> He didn’t know what he should do
We will ask when to set off >>> We will ask when we should set off

-- When the subject of the to-infinitive is the same as the person spoken to:

Nobody told me what to do. >>> Nobody told me what I should do.
Can anyone suggest where to go for lunch? >>> Can anyone suggest [to us] where we should go for lunch.

  • after some nouns to say more about the noun:

Is there any reason why I should stay?.
Do you remember the day when we went to Edinburgh.
That was the town where I grew up.

We often use a wh-clause after is:

I missed my bus. That’s why I was late.
This is where I live.
That’s what I thought.
Paris – that’s where we are going for our holidays.





I am not sure if my question is within the scope of this article but I am searching for it everywhere and I just cannot find it. :(
Why is Wh-words forbidden in relative infinite clauses?
*Days that to eat in the garden is possible are gone.
Why is exactly this sentence ungrammatical? (I really need to understand theory behind it, I know it's ungrammatical cause it sounds weird but that's about it.)
Thank you in advance for any help and explanation you can provide.

Hello Jessmine,

I'm afraid I'm not sure I understand this sentence or what you mean by 'infinite clauses'. Does it mean that the days when it was possible to eat in the garden are gone? If so, we don't normally use the infinitive to make a verb into a noun, so I'd recommend 'eating' instead of 'to eat'. Then, since it's really a statement about time, I'd recommend 'when' instead of 'that'. Then, if the eating in the garden was only possible in the past, then 'was' should be used instead of 'is'.

I hope this helps you.

All the best,
The LearnEnglish Team

Thank you very much for your answer!
My problem lied in to eat/eating problem. And because I overheard somewhere that you generally dont use to-inf after wh-words. But it seems the problem lies elsewhere. In noun is it?
Once again thanks for answering my confusing comment.

Hello Jessmine,

I'm afraid that we don't really understand what it is that you are trying to say with your sentence. It has multiple problems and while we could guess what you want to say and try to construct the sentence for you we have no way of knowing if those guesses are correct. We could end up misleading you in that way.

If you can tell us clearly what it is that you want to express then we can try to help you to say it and can perhaps explain why your sentence is not the right way to say it.


Best wishes,


The LearnEnglish Team

I’d like to ask about how to answer ‘whose’ questions.

Whose phone is this?
It is Tom’s.

Is it a must to use ‘it is’ to respond that question?
Can I say this is Tom’s instead?
Many thanks

Hi libero,

Using this in your answer is not grammatically incorrect but the standard response is it. We would use this or that when we need to distinguish one item from another:

Whose desk is this?

That's mine. This one is yours.


Best wishes,


The LearnEnglish Team

Hello. Can we use a mixture of wh- clauses in a sentence? Is there any rules to include more than one?
I have repeatedly noticed how students who have attended mixed- gender schools in childhood get embarrassed when interacting and socializing at higher educational levels.

Hello Tahereh,

Yes, you can use a variety of wh-clauses in the same sentence. Your example sentence is grammatically correct and makes perfect sense -- good work! Although some combinations probably don't work, as far as I know, there are particular rules governing the use of multiple wh-clauses in the same sentence. If you have any other example sentences you'd like to ask us about, we're happy to help you with them, though.

All the best,
The LearnEnglish Team

Dear Kirk,
Thank you very much for your kind guidance.
Here l made two examples which might seem funny. Of course, the sentences could be rewritten in a better way, but l' ve made them just for the sake of learning:
1. The person whom l saw yesterday was the one who broke the law and didn't know how to park the car as well as when to switch-off the engine, while the car was still consming petrol.

2. The person whom l saw yesterday was the one who broke his leg and didn't know where to go as well as whom to show his leg, and inquire about what pain killer to take.

Thanks for your patience in reading!

Hello Tahereh,

The use of wh-clauses in these sentences is fine. Good work!

When 'who' or 'whom' can be omitted (e.g. 'The person I saw yesterday'), it generally is and especially in sentence with lots of clauses. But I expect you know that and were including it on purpose.

Best wishes,
The LearnEnglish Team