Time Clauses

When

(Used in questions) at what time; on what occasion: When did you last see him? When can I see you? When (= in what circumstances) would such a solution be possible?
Used after an expression of time to mean "at which" or "on which": Sunday is the only day when I can relax. There are times when I wonder why I do this job.
At which time; on which occasion: The last time I went to Scotland was in May, when the weather was beautiful.
What / which time: Until when can you stay? "I've got a new job. Since when?"

• At or during the time that: I loved history when I was at school.
• After: Call me when you've finished.
• At any time that; whenever: Can you spare five minutes when it's convenient?
• Just after which: He had just drifted off to sleep when the phone rang.
• Considering that: How can they expect to learn anything when they never listen?
• Although: She claimed to be 18, when I know she's only 16.

While

During the time that sth is happening. SYN when: We must have been burgled while we were asleep. Her parents died while she was still at school. While I was waiting at the bus stop, three buses went by in the opposite direction.
At the same time as sth else is happening: You can go swimming while I'm having lunch. Shoes mended while you wait
Used to contrast two things: While Tom's very good at science, his brother is absolutely hopeless.
(Used at the beginning of a sentence) although; despite the fact that...: While I am willing to help, I do not have much time available.
Until: I waited while six o'clock.
While you're / I'm etc. at it: used to suggest that sb could do sth while they are doing sth else: "I'm just going to buy some postcards. Can you get me some stamps while you're at it?"
[Sing.] A period of time: They chatted for a while. I'll be back in a little while (= a short time). I haven't seen him for quite a while (= a fairly long time). They walked back together, talking all the while (= all the time).
While sth away: to spend time in a pleasant lazy way: We whiled away the time reading and playing cards.

Until/ Till

Until: (Also Informal till) up to the point in time or the event mentioned: Let's wait until the rain stops. Until she spoke I hadn't realized she wasn't English. You're not going out until you've finished this. Until now I have always lived alone. He continued working up until his death. The Street is full of traffic from morning till night. You can stay on the bus until London (= until you reach London).
Till: We're open till 6 o'clock. Can't you wait till we get home? Just wait till you see it. It's great.
"Till" is generally felt to be more Informal than "Until" and is used much less often in writing. At the beginning of a sentence, until is usually used.

Soon

In a short time from now; a short time after sth else has happened: We'll be home soon. / We'll soon be home. She sold the house soon after her husband died. I soon realized the mistake. It soon became clear that the programme was a failure. (Informal) See you soon!
Early: quickly: How soon can you get here? We'll deliver the goods as soon as we can. Please send it as soon as possible. Next Monday is the soonest we can deliver. They arrived home sooner than expected. The sooner we set off, the sooner we will arrive.
No sooner said than done: used to say that sth was, or will be, done immediately.
No sooner... than...: used to say that sth happens immediately after sth else: No sooner had she said it than she burst into tears.
The sooner the better: very soon; as soon as possible: "When shall I tell him? The sooner the better."
Sooner or Later: at some time in the future, even if you are not sure exactly when: Sooner or later you will have to make a decision.
Sooner rather than later: after a short time rather than after a long time: We urged them to sort out the problem sooner rather than later.

Long

Lasting or taking a great amount of time or more time than usual: He's been ill (for) a long time. I like it now the days are getting longer (= it stays light for more time each day). A long book / film / list (= taking a lot of time to read / watch / deal with) Nurses have to work long hours (= for more hours in the day than is usual). (NAmE) He stared at them for the longest time (= for a very long time) before answering.
Used for asking or talking about particular periods of time: How long is the course? I think it's only three weeks long. How long a stay did you have in mind?
Seeming to last or take more time than it really does because, for example, you are very busy or not happy: I'm tired. It's been a long day. We were married for ten long years.
At long last: after a long time. SYN finally: At long last his prayers had been answered.
At the longest: not longer than the particular time given: It will take an hour at the longest.
Go back a long way: (of two or more people) to have known each other for a long time: We go back a long way, he and I.
Go a long way: (of money, food, etc.) to last a long time: She seems to make her money go a long way. A small amount of this paint goes a long way (= covers a large area). (Ironic) I find that a little of Jerry's company can go a long way (= I quickly get tired of being with him).
In the long run: concerning a longer period in the future: This measure inevitably means higher taxes in the long run.
Long time no see: (Informal) used to say hello to sb you have not seen for a long time.
Take the long view (of sth): to consider what is likely to happen or be important over a long period of time rather than only considering the present situation.
As / so long as

• Only if: We'll go as long as the weather is good.
• Since: to the extent that: So long as there is a demand for these drugs, the financial incentive for drug dealers will be there.

For (so) long: for (such) a long time: Will you be away for long? I'm sorry I haven't written to you for so long.
Long live sb/sth: used to say that you hope sb/sth will live or last for a long time.
(For) long / (for) a long time
Both (for) long and (for) a long time are used as expressions of time. In positive sentences (for) a long time is used: We've been friends a long time. (For) long is not used in positive sentences unless it is used with too, enough, as, so, seldom, etc.: I stayed out in the sun for too long. You've been waiting long enough. Both (for) long and (for) a long time can be used in questions, but (for) long is usually preferred: Have you been waiting long?
In negative sentences (for) a long time sometimes has a different meaning from (for) long: Compare: I haven't been here for a long time (= It is a long time since the last time I was here) and I haven't been here long (= I arrived here only a short time ago).