Collins COBUILD Advanced Learner's English Dictionary - must

(musts) Frequency: The word is one of the 700 most common words in English. 1. You use must to indicate that you think it is very important or necessary for something to happen. You use must not or mustn’t to indicate that you think it is very important or necessary for something not to happen. What you wear should be stylish and clean, and must definitely fit well... The doctor must not allow the patient to be put at risk... MODAL 2. You use must to indicate that it is necessary for something to happen, usually because of a rule or law. Candidates must satisfy the general conditions for admission... Equipment must be supervised if children are in the house. MODAL 3. You use must to indicate that you are fairly sure that something is the case. At 29 Russell must be one of the youngest ever Wembley referees... I’m sure he must feel he has lost a close family friend, because I know I do... I must have been a bore. MODAL 4. You use must, or must have with a past participle, to indicate that you believe that something is the case, because of the available evidence. ‘You must be Emma,’ said the visitor... Miss Holloway had a weak heart. She must have had a heart attack... MODAL 5. If you say that one thing must have happened in order for something else to happen, you mean that it is necessary for the first thing to have happened before the second thing can happen. In order to take that job, you must have left another job... MODAL 6. You use must to express your intention to do something. I must be getting back... I must telephone my parents... He told the Prime Minister that he felt he must now leave. MODAL 7. You use must to make suggestions or invitations very forcefully. You must see a doctor, Frederick... You must see the painting Paul has given me as a wedding present... MODAL 8. You use must in remarks and comments where you are expressing sympathy. This must be a very difficult job for you... MODAL 9. You use must in conversation in expressions such as ‘I must say’ and ‘I must admit’ in order to emphasize a point that you are making. This came as a surprise, I must say... I must admit I like looking feminine... MODAL c darkgreen]emphasis 10. You use must in expressions such as ‘it must be noted’ and ‘it must be remembered’ in order to draw the reader’s or listener’s attention to what you are about to say. It must be noted, however, that not all British and American officers carried out orders... It must be stated that this illness is one of the most complex conditions known to man. MODAL 11. You use must in questions to express your anger or irritation about something that someone has done, usually because you do not understand their behaviour. Why must she interrupt?... Must you always run when the pressure gets too much? MODAL c darkgreen]feelings 12. You use must in exclamations to express surprise or shock. ‘Go! Please go.’—‘You must be joking!’... I really must be quite mad!... MODAL c darkgreen]emphasis 13. If you refer to something as a must, you mean that it is absolutely necessary. (INFORMAL) The new 37th issue of National Savings Certificates is a must for any taxpayer... N-COUNT: usu a N in sing 14. You say ‘if you must’ when you know that you cannot stop someone doing something that you think is wrong or stupid. If you must be in the sunlight, use the strongest filter cream you can get... ‘Could I have a word?’—‘Oh dear, if you must.’... PHRASE: usu PHR inf 15. You say ‘if you must know’ when you tell someone something that you did not want them to know and you want to suggest that you think they were wrong to ask you about it. ‘Why don’t you wear your jogging shorts Mum?’—‘Well, my legs are too skinny, if you must know.’ PHRASE: PHR with cl