Collins COBUILD Advanced Learner’s Dictionary

2 CONJ You use what after certain words, especially verbs and adjectives, when you are referring to a situation that is unknown or has not been specified. □  You can imagine what it would be like driving a car into a brick wall at 30 miles an hour. □  I want to know what happened to Norman. □  Do you know what those idiots have done? □  We had never seen anything like it before and could not see what to do next. □  She turned scarlet from embarrassment, once she realized what she had done. ● DET What is also a determiner. □  I didn't know what college I wanted to go to. □  I didn't know what else to say. □  …an inspection to ascertain to what extent colleges are responding to the needs of industry.

3 CONJ You use what at the beginning of a clause in structures where you are changing the order of the information to give special emphasis to something. [EMPHASIS ] □  What precisely triggered off yesterday's riot is still unclear. □  What I wanted, more than anything, was a few days' rest.

4 CONJ You use what in expressions such as what is called and what amounts to when you are giving a description of something. □  She had been in what doctors described as an irreversible vegetative state for five years.

5 CONJ You use what to indicate that you are talking about the whole of an amount that is available to you. □  He drinks what is left in his glass as if it were water. ● DET What is also a determiner. □  They had to use what money they had.

6 CONVENTION You say ' What? ' to tell someone who has indicated that they want to speak to you that you have heard them and are inviting them to continue. [SPOKEN , FORMULAE ] □  'Dad?'—'What?'—'Can I have the car tonight?'

7 CONVENTION You say ' What? ' when you ask someone to repeat the thing that they have just said because you did not hear or understand it properly. 'What?' is more informal and less polite than expressions such as 'Pardon?' and 'Excuse me?'. [SPOKEN , FORMULAE ] □  'They could paint this place,' she said. 'What?' he asked.

8 CONVENTION You say ' What ' to express surprise. [FEELINGS ] □  What! You want Saturday off as well?

9 PREDET You use what in exclamations to emphasize an opinion or reaction. [EMPHASIS ] □  What a horrible thing to do. □  What a busy day. ● DET What is also a determiner. □  What ugly things; throw them away! □  What great news, Jakki.

10 ADV [ADV n] You use what to indicate that you are making a guess about something such as an amount or value. □  It's, what, eleven years or more since he's seen him.

11 CONVENTION You say guess what or do you know what to introduce a piece of information which is surprising, which is not generally known, or which you want to emphasize. □  Guess what? I'm going to dinner at Mrs. Combley's tonight.

12 PHRASE In conversation, you say or what? after a question as a way of stating an opinion forcefully and showing that you expect other people to agree. [EMPHASIS ] □  Look at that moon. Is that beautiful or what? □  Am I wasting my time here, or what?

13 CONVENTION You say so what? or what of it? to indicate that the previous remark seems unimportant, uninteresting, or irrelevant to you. [FEELINGS ] □  'I skipped off school today,'—'So what? What's so special about that?' □  'You're talking to yourself.'—'Well, what of it?'

14 PHRASE You say ' Tell you what ' to introduce a suggestion or offer. □  Tell you what, let's stay here another day.