Definition of when in US English:



  • 1At what time.

    ‘when did you last see him?’
    with preposition ‘since when have you been interested?’
    • ‘He would not discuss when or how the information was given to him.’
    • ‘You have to learn when your Tamagotchi needs food, when it needs to sleep, when it wakes up.’
    • ‘We don't know when the pub will reopen, although we hope it will be as soon as possible.’
    • ‘Although there are a number of ways to predict when this is, they are not entirely reliable.’
    • ‘This is as well as not knowing when they will arrive.’
    • ‘He said it was expected to be reopened to pedestrians today but it was not yet clear when it would open to traffic.’
    • ‘So has Paul, and we were trying to work out in the changing room when we'd each last been.’
    1. 1.1 How soon.
      ‘when can I see you?’
      • ‘When can I see you?’
    2. 1.2 In what circumstances.
      ‘when would such a rule be justifiable?’
      • ‘I was moving to Dublin and nobody was going to tell me when and where to smoke.’
      • ‘When will we meet again?’

relative adverb

  • At or on which (referring to a time or circumstance)

    ‘Saturday is the day when I get my hair done’
    • ‘Cancun has shown once again that we are living in a time when great struggles are shaping history.’
    • ‘The day when you could open your windows for fresh air is just a dim memory.’
    • ‘There were times when he crossed the finish line and found himself hanging out the side, unaware of where he was.’
    • ‘It was best not to provoke them, and others like them, at a time when maximum unity was necessary.’
    • ‘Falls are most common in the summer, when people sleep outside on their roofs to keep cool.’
    • ‘It was a day when global warming showed that it can survive even in the face of a westerly gale.’
    • ‘As a matter of fact there were nights when I drove to my sister across town to get ice.’
    • ‘We must not return to the days when former Home Secretaries cut police numbers.’
    • ‘There are times when although there are no absolute values you simply have to act as though there are.’
    • ‘It's that time of year when gimmicky wines with daft labels burst upon us in the supermarkets.’
    • ‘Meopham Tennis Club will be having an open day this Sunday when it will be offering free coaching.’
    • ‘The days are long past when independent schools were the preserve of Lord Snooty and his pals.’
    • ‘There are moments when Caribbean winds, normally an elixir, get a bit out of hand.’
    • ‘She has literally waited for the minute when we turned our backs and seized the moment.’
    • ‘There have been times when Given was considered not to be the best keeper at Newcastle.’
    • ‘Although we always want things, childhood is the time when we are most insistent.’
    • ‘On a day when big stories leapt off the leaderboard, Donald was among the best.’
    • ‘I'm still sure that one of the finest days in his life was when they opened a kebab machine in the Union.’
    • ‘There comes a time in every rich artist's life when they may consider changing careers.’
    • ‘It is one of those times when outstanding actors have a great time doing a decent film.’
    as soon as, the moment, the instant, the second, once, when, immediately after
    View synonyms


  • 1At or during the time that.

    ‘I loved math when I was in school’
    • ‘He urged people to keep mobile phones out of sight when not in use, and to use them to make essential calls only.’
    • ‘His father took him to Tynecastle when he was five, to see a Hearts and Hibs game.’
    • ‘The option is one of three for the three main party leaders to consider when they meet at City Hall.’
    • ‘Although for a couple of years when I was a child my whole family decided not to eat meat.’
    • ‘Now he goes to bed late because he is frightened of nightmares when he sleeps.’
    • ‘Although they cannot see fully yet, they listen intently when we tell them of these things.’
    • ‘The man's whole life should have been considered when the decision was made to give the award out.’
    • ‘He was looking out the front door yesterday when I had it open to feed the hens.’
    • ‘The first time I used a personal shopper was five years ago, when I lived in Toronto.’
    • ‘That's what my Scottish grandmother told me I needed to do when I was five years old.’
    • ‘I'll never forget idly thumbing through a bible in a hotel room when I was a child.’
    • ‘His father was operating on a cat in the room below when he saw his son hurtle to the ground.’
    • ‘Theatre is her first love and when she is not performing she can invariably be found among the audience.’
    • ‘One survivor said a meeting was being held in an upstairs room when the blast occurred.’
    • ‘He told police that he used it because it helped him sleep when he was coming off heroin.’
    • ‘They shared a room when they were on tour and off the field they were big buddies.’
    • ‘It was years after these events that I found out my Aunt died in that room when she was only 14.’
    • ‘In the early days after the birth, it can be useful to set aside some time to rest when the baby sleeps.’
    • ‘His dad left when he was very young, although he patched things up before he died.’
    • ‘All too often as adults, we cease to give it any attention or value, except at night when we sleep and we dream.’
    1. 1.1 After.
      ‘call me when you're finished’
      • ‘Already we've had a lot of people in asking about Nemos, and when the film opens that will triple.’
      • ‘Perhaps the first thing I see when I open my curtains will make the decision for me.’
      • ‘We are going to make her a book-nook in her room when we move and this cushion is a good start.’
      • ‘The chief safety scientist of American phone companies was sacked when he found out too much.’
      • ‘I was fed up of having to avoid certain foods and when I finished the chicken I felt guilty.’
      • ‘There was silence in the room when she finished her description of her trip to Africa.’
      • ‘Central banks last night said that they were ready to offer liquidity when markets open today.’
      • ‘It is much needed because where are people meant to buy groceries when they finish work or at weekends?’
      • ‘A representative of the team paid a visit to the shop when it opened in the week before Christmas.’
      • ‘Although we were a little disappointed when it turned out to be the same colour as our long termer!’
      • ‘David had to postpone any college plans he may have had when his uncle died suddenly.’
      • ‘I took them round a present and a card not long ago when the new baby arrived.’
      • ‘Ideally, you start it when you arrive, and you finish sometime before you go on stage to show it.’
      • ‘A colleague found him dead in bed after breaking into his room when he did not turn up for work.’
      • ‘In retrospect, I wish I'd got someone at the other end of the room to call me when he set off.’
      • ‘Demophoon and Phyllis fell in love when his ship was washed ashore in a storm.’
      • ‘We got a couple of tickets out to the middle of nowhere and boarded the train when it arrived.’
      • ‘I said when I arrived here on Wednesday night that I felt the hand of history upon us.’
      • ‘Louise Welsh faced facts when she left Glasgow University with a degree in history.’
      • ‘He once sneaked into the woman's home while she was sleeping, only fleeing when she woke up.’
    2. 1.2 At any time that; whenever.
      ‘can you spare five minutes when it's convenient?’
      • ‘It is a sad fact that, when it comes to sensitivity to attack, there is no one so sensitive as a journalist.’
      • ‘They need, too, to be open when people are inclined to use them, including Sundays.’
      • ‘They seem only ever to get an opposing view when a speaker says something with which they disagree.’
      • ‘I love it when the web makes you take more notice of things in the real world.’
      • ‘It has vanished into the black cyber hole where all blogs go when they're not being noticed.’
      • ‘In fact, when I pass the police station at night the door is always closed and no lights to be seen.’
      • ‘There are certain terms that car manufacturers love to use when pushing their latest wares.’
      • ‘I used to love that song when it was played on the old Saturday morning radio programmes for kids.’
      • ‘She can smoke as much as she wants when in her room and we get on just fine.’
      • ‘I have a fund of somewhat boring stories which I tell myself when sleep is slow to come.’
      • ‘If grown on a window ledge, it may be necessary to bring the plants into the room at night when there is frost.’
      • ‘Although I am serious when the situation demands it, I try to be jolly to give people a bit of a lift.’
      • ‘Opinion is divided on what can be done to keep the roads open when it snows.’
      • ‘For reasons such as these we must take great care when a particular moral view claims to be Biblical.’
      • ‘It is the policy of the school not to open when the roads are very icy in the interest of safety.’
      • ‘You slept when you could, but you were always awake at first and last light in case of a surprise attack.’
      • ‘She used to shout at the children when they left the room with it still on.’
      • ‘He loved a laugh and when he was in a crowd he was the life and soul of the party.’
      • ‘The device covers the gap created on a door hinge when it is open and prevents fingers being trapped in the door.’
      • ‘You may not know it, but it really does matter where you sleep when you are away from home.’
  • 2After which; and just then (implying suddenness)

    ‘he had just drifted off to sleep when the phone rang’
    • ‘Melanie had been at work in her new job for 15 minutes when the plane hit the north tower.’
    • ‘She was just slipping into the realm of sleep when a slight rustling woke her.’
    • ‘We had been talking and laughing a great deal for more than half an hour when suddenly the lady burst into tears.’
    • ‘They were considering going scuba diving when the tsunami devastated the coastline.’
    • ‘Tony was in the kitchen sorting out a cup of tea, a tinny and a few snacks when he suddenly became quite excited.’
    • ‘The centre was only open a week when it was forced to close because of dumping on the site.’
    • ‘The helicopter was airborne for only a minute when it started plunging toward the river.’
    • ‘I had just nodded off to sleep when I was woken up by an almighty crash from their house.’
    • ‘He was about to dictate into his recorder about the progress of his work when his mobile phone rang.’
    • ‘He had been behind the counter for less than two minutes when he thought the stall had been hit by an earthquake.’
    • ‘I had gone back to check some facts when Angier emerged awkwardly from the bathroom.’
    • ‘Mr Clark was preparing Sunday lunch when he opened the oven door and a fireball leapt into the air.’
    • ‘Astor was just about to reclaim his travelling bag and unpack when the phone began to ring.’
    • ‘Devlin just followed her out into his bedroom, when his cell phone started ringing.’
    • ‘They had not been gone for five minutes when the discussion of their private lives began.’
    • ‘Owen was about to cross the room to comfort her when there was a knocking on the door.’
    • ‘It was late in the night, and Jim was just about to drift off to sleep, when Ellen rolled over.’
    • ‘York matched Wharfedale until the last five minutes when they notched a decisive try.’
    • ‘We were there only minutes when a drug dealer turned up and handed round cannabis.’
    • ‘The other evening I was moving across our sitting room when I felt to be falling forward.’
  • 3In view of the fact that; considering that.

    ‘why bother to paint it when you can photograph it with the same effect?’
    • ‘Seemingly not, although it does not help when they are not in a position to keep up with the play.’
    • ‘You cannot claim to give the facts straight when there is no-one giving the other view.’
    • ‘She didn't think Jamie was the type to sit hiding in some motel room when someone was out to kill him.’
    • ‘It's hard not be cynical about the power of love when there is so much bile around.’
    • ‘Where was the body, I used to think, when there is no room between the headstone and the wall?’
    • ‘Can we define terrorism when one man's freedom fighter is another man's terrorist?’
    • ‘There is no room to manoeuvre when the character of a space determines the environment.’
    • ‘I am in the fourth year of my own fight, which is considered a long time when you have the kind of cancer I have.’
    • ‘Why sleep with that woman when you know it could bring you trouble somewhere down the line?’
    • ‘Was it really worth those few minutes of peace when he knew he was slowly killing himself?’
    • ‘For what chance is there of love when everything you do is monitored as if on CCTV?’
    • ‘I never try to convince my body that it should be sleeping when it knows better.’
    • ‘To rely on a phone call from California when so many lives are at stake is not enough.’
    • ‘So why did she look over the glasses to get a good view of me when previously the glasses had done the job?’
    • ‘I mean who else is there to take up the slack for them, when their fifteen minutes of fame is running out.’
    • ‘It is fantastic to even consider him when he has not been a pupil for two years.’
    • ‘Why does Dolan persist in five at the back when it clearly doesn't suit York's style of play?’
    • ‘How can there be love when you leave me, without warmth and without explanation?’
  • 4Although; whereas.

    ‘I'm saying it now when I should have told you long ago’
    • ‘I had this idea of him being loud and brash when in fact he's laidback and quiet with this fantastic wit.’
    • ‘It looks as though it was made at a particular time when in fact it was made 24 hours later.’
    • ‘I had thought that this wasn't working, when in fact it was only not working in Firefox.’
    • ‘They behaved as if they were in their living room at home, when, clearly they weren't.’
    • ‘I think we fall back too often on our power when in fact we probably could do more by persuasion.’
    • ‘People were led to believe they had won a top prize when in fact they were being induced to pay for a low value product.’
    • ‘Somehow that statistic came to be portrayed as a bad thing, when in fact it is a heartening trend.’
    • ‘People could at times be standing at the back when there was room in the front of the train.’
    • ‘My flushed cheeks illustrated my shyness, when in fact it was sheer frustration.’
    • ‘The danger is trying to put your nose through when there is no room and it ends in an accident.’
    • ‘It is easy to ask a very general question when in fact what is wanted is a response to a specific issue.’
    • ‘They may it look as though it is a charitable collection when in fact they are going to sell the stuff off.’


Old English hwanne, hwenne; of Germanic origin; related to German wenn ‘if’, wann ‘when’.