- couldW1S1 [kəd strong kud] modal v negative short form couldn't▬▬▬▬▬▬▬1¦(past ability)¦2¦(possibility)¦3¦(emphasizing your feelings)¦4¦(requesting)¦5¦(suggesting)¦6¦(annoyance)¦7 couldn't be better/worse/more pleased etc8 I couldn't9 could do with something▬▬▬▬▬▬▬[: Old English; Origin: cuthe, past tense of cunnan ( CAN1); influenced by should and would]1.) ¦(PAST ABILITY)¦used as the past tense of 'can' to say what someone was able to do or was allowed to do in the past▪ By the time she was eight, she could read Greek and Latin.▪ In those days you could buy a box of cigars for a dollar.▪ Could you hear what I was saying?▪ I couldn't get tickets after all, they were sold out.▪ I knew I couldn't afford the rent.▪ The teacher said we could all go home.2.) ¦(POSSIBILITY)¦a) used to say that something is possible or might happen▪ Most accidents in the home could be prevented.▪ It could be weeks before we get a reply.▪ If you're not careful, you could get into even worse trouble.▪ A faulty connection could easily (=would be likely to) cause a fire.b) used to say that something was a possibility in the past, but did not actually happen▪ Somebody could have been killed.▪ I could have warned you if I had known where you were.▪ He could have escaped, but he chose to stand and fight.3.) ¦(EMPHASIZING YOUR FEELINGS)¦spoken used to emphasize how happy, angry etc you are by saying how you want to express your feelings▪ Sometimes he irritates me so much I could scream.▪ I was so angry I could have killed her.▪ I was so relieved I could have kissed them all.4.) ¦(REQUESTING)¦spoken used to make a polite request▪ Could you help me with these boxes?▪ Could I have a drink of water, please?▪ How about Sam? Could he come along too?▪ I wonder if I could just ask you to sign this.5.) ¦(SUGGESTING)¦used to suggest doing something▪ You could ask your doctor for a check-up.▪ You could always try phoning her at the office.▪ Maybe we could get together sometime next week?▪ Couldn't you get one of your friends to help you?6.) ¦(ANNOYANCE)¦spoken used to show that you are annoyed about someone's behaviour▪ You could have told me you were going to be late (=you should have told me but you did not) !▪ You could at least say that you're sorry.▪ How could you be so stupid!7.) couldn't be better/worse/more pleased etcused to emphasize how good, bad etc something is▪ Their lifestyles couldn't be more different.▪ 'How are things?' 'Fine! Couldn't be better.'▪ Ordering on-line couldn't be simpler.8.) I couldn'tBrE spoken used to politely say that you do not want any more food or drink▪ 'Would you like another piece of pie?' 'Oh, no thanks, I couldn't.'9.) could do with sthspoken to need or want something▪ I could do with a hot drink.→could do worse (than) at ↑worse1 (5)→couldn't care less at ↑care2 (5)→couldn't agree more at ↑agree
Dictionary of contemporary English. 2013.