Lesson
The usage of some English prepositions
For, during and while
We use for + a period of time to say how long something goes on:
A. For
For two hours, for a week, for ages for example:
* We watched television for two hours last night.
* Victoria is going away for a week in September.
* Where have you been? I've been waiting for ages.
* Are you going away for the weekend?
We use during + noun to say when something happens (not how long):
During the movie during our holiday during the night
For example:
* I fell asleep during the movie.
* We met a lot of people during our holiday.
* The ground is wet. It must have rained during the night.
With a 'time word' (for example, the morning/the afternoon/the summer), you can usually say in or during:
* It must have rained in the night. (or ... during the night.)
* I'll phone you sometime during the afternoon. (or ... in the afternoon.)
You cannot use during to say how long something goes on:
* It rained for three days without stopping. (not 'during three days')
Compare during and for:
* I fell asleep during the movie . I was asleep for half an hour.
B. During and while
Compare:
We use during + noun:
I fell asleep during the movie .
Compare during and while in these examples:
* We met a lot of interesting people during our holiday.
* Robert suddenly began to feel ill during the examination.
We use while + subject + verb:
* I fell asleep while I was watching television.
* We met a lot of interesting people while we were on holiday.
* Robert suddenly began to feel ill while he was doing the examination.
Some more examples of while:
* We saw Amanda while we were waiting for the bus.
* While you were out, there was a phone call for you.
* Christopher read a book while I watched television.
When you are talking about the future, use the present (not 'will') after while:
* I'll be in London next week. I hope to see Tom while I'm there. (not 'while I will be there')
* What are you going to do while you are waiting? (not 'while you will be waiting')
By and until, by the time...
A. By (+ a time) ='not later than':
* I posted the letter today, so they should receive it by Monday. (= on or before Monday, not later than Monday)
* We'd better hurry. We have to be at home by 5 o'clock. (=at or before 5 o'clock, not later than 5 o'clock)
* Where's Sue? She should be here by now. (=now or before now - so she should have arrived already)
You cannot use until with this meaning:
* Tell me by Friday whether or not you can come to the party. (not 'Tell me until Friday')
B. We use until (or till) to say how long a situation continues:
* 'Shall we go now?' 'No, let's wait until (or till) it stops raining.'
* I couldn't get up this morning. I stayed in bed until half past ten.
* I couldn't get up this morning. I didn't get up until half past ten.
Compare until and by:
#1 until
Something continues until a time in the future:
* Fred will be away until Monday. (so he'll be back on Monday)
* I'll be working until 11. 30. (so I'll stop working at 11.30)
#2 by
Something happens by a time in the future:
* Fred will be back by Monday. (= he'll be back not later than Monday)
* I'll have finished my work by 11. 30. (I'll finish my work not later than 11. 30)
C. You can say 'by the time something happens'. Study these examples:
* It's not worth going shopping now. By the time we get to the shops, they will be closed. (= the shops will close between now and the time we get there)
* (from a letter) I'm flying to the United States this evening. So by the time you receive this letter, I'll be in New York. (= I will arrive in New York between now and the time you receive this letter)
* Hurry up! By the time we get to the cinema, the movie will already have started.
You can say 'by the time something happened"(for the past):
* Jane's car broke down on the way to the party last night. By the time she arrived, most of the other guests had gone. (= it took her a long time to get to the party and most of the guests went home during this time)
* I had a lot of work to do yesterday evening. I was very tired by the time I finished. (= it took me a long time to do the work and I became more and more tired during this time)
* We went to the cinema last night. It took us a long time to find somewhere to park the car. By the time we got to the cinema, the movie had already started.
Also by then or by that time:
* Jane finally arrived at the party at midnight, but by then (or by that time), most of the guests had gone.
At /on / in (time)
A. Compare at, on and in:
* They arrived at 5 o'clock.
* They arrived on Friday.
* They arrived in October. /They arrived in 1968.
We use:
At for the time of day:
At 5 o'clock, at 11.45, at midnight, at lunchtime, at sunset etc.
On for days and dates:
On Friday/on Fridays, on 12 March 1991, on Christmas Day, on my birthday
In for longer periods (for example, months/years/seasons):
in October, in 1968, in the 18th century, in the past, in (the) winter, in the 1970s, in the Middle Ages, in (the) future
B. We use at in these expressions:
At night: I don't like going out at night.
At the weekend/at weekends: Will you be here at the weekend?
At Christmas/at Easter (but on Christmas Day): Do you give each other presents at Christmas?
At the moment/at present: Mr Benn is busy at the moment/at present.
At the same time: Liz and I arrived at the same time.
Note that we usually ask 'What time ... ?' (not usually 'At what time...?):
* What time are you going out this evening?
C. We say:
In the morning(s), in the afternoon(s), in the evening(s)
* I'll see you in the morning.
* Do you work in the evenings?
But:
On Friday morning(s), on Sunday afternoon(s), on Monday evening(s) etc.
* I'll be at home on Friday morning.
* Do you usually go out on Saturday evenings?
D. We do not use at/on/in before last/next/this/every:
* I'll see you next Friday. (not 'on next Friday')
* They got married last March.
E. In a few minutes/in six months etc. = a time in the future
* The train will be leaving in a few minutes. (= a few minutes from now)
* Jack has gone away. He'll be back in a week. (= a week from now)
* She'll be here in a moment. (= a moment from now)
You can also say 'in six months' time', 'in a week's time' etc.:
* They're getting married in six months' time. (or ... in six months.)
We also use in... to say how long it takes to do something:
* I learnt to drive in four weeks. (It took me four weeks to learn)
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Mr. Firass Kaddour
Syria