Sunday, November 11, 2012

Time clauses

The term Time Clause is usually used for adverbial subordinate clauses which link an event in that clause to another event in the main clause in a time relationship. They answer the question when? Time clauses cannot stand alone except as an answer to a question.
  • Mary made lunch after she had done the shopping.
  • When did Mary make lunch?
  • After she had done the shopping.
Time clauses start with a conjunction -
when, whenever, while, once, before, after, as, (ever) since, until, as soon as, now (that), the moment (that)
The time clause can come before or after the main clause. When it comes before, it is usually followed by a comma. But if the main course comes first, no comma is used.
  • After she had done the shopping, Mary made lunch.
  • Mary made lunch after she had done the shopping.
Mainly through the use of exercises, this post deals with:
  • Time clauses - which conjunction to use
  • The use of tenses in time clauses
  • Reducing time clauses
  • Other clauses that express a time relationship

Which conjunction?

  • things happening at the same time - while, when, as
  • one thing happening after another - after, before, as soon as, when, once etc
  • one thing happening very quickly after another - immediately, the moment / minute (that)
  • every time - when, whenever, every time
  • when things started - since, ever since
  • when things finish - until, by the time

as, when and while

1. Simultaneous actions

  • We can use as, when or while to talk about a longer 'background' action taking place when something else happens.
  • While Sammy was working in the garden, his dog suddenly started barking for no apparent reason.
  • Somebody knocked at the door when we were having supper.
  • As she lay reading in bed, she heard one of the children shout something.
  • We usually use a continuous tense for the longer action but can use as and while with simple tenses with verbs like sit, lie or grow, which describe continuous actions or states.
  • We prefer while (but not when) when we want to talk about two longer actions happening at the same time:
  • I'll do the washing up while you're putting the kids to bed.
  • While she was studying at college, she stayed in the Halls of Residence.
  • We prefer as (with simple tenses) when we want to say that something changes at the same time as something else:
  • As you stir the batter mixture, it will thicken to the consistency of cream.
  • You'll find it gets easier as you get more experience.
  • We use when (but not as or while to talk about things that happened at a particular time in our life or in the past:
    When I was a child, we lived in the country .
    The Romans built a lot of roads when they ruled Britain.
  • We can also use when to mean something like and then. Compare these two sentences:
  • When Sammy was watching televison, his dog suddenly started barking.
  • Sammy was watching televison, when his dog suddenly started barking.
  • The meaning here is exactly the same, but in the first sentence when means something like at the time, while in the second it means something more like and then. We can only do this with when, not as or while.

2. Consecutive actions

  • We use when (but not as or while) to talk about one action happening immediately after another
  • When he finished lunch, he went out for a walk.
  • I suspected something was wrong when I saw the look on his face.
  • We use as or when but not (while) when we want to emphasise that two short events happen at almost the same time. We often add just
  • As she turned the corner, she saw a crowd of people marching up the street.
  • A police car pulled up outside the house just as I arrived home.
  • You'll see the taxis just as you come out of the station.

3. Every time

  • We use when (but not as or while) to mean whenever - every time
  • When I visit London, I always stay with my sister.
  • I have a coffee when I've had my shower.


  • We use once to mean after something has happened, or to say that one thing has to happen before another can happen - when and only when, or to mean as soon as. It's often used with a perfect tense:
  • What will you do once you retire?
  • Once he'd finished making the model airplane, he started to paint it.
  • Give me a call once you've arrived.

before and until

  • We use before to talk about a short action happening before another action, and which doesn't necessarily last right up until the time of the second action
  • They got married before they moved here.
  • Before I had a chance to say anything, she turned on her heels and left.
  • He's taking a year out before he goes to university.
  • We use until to talk about a longer action which lasts up to the time of the second action, or when the second action is the result of the first
  • She's staying with us until she can find a new flat.
  • He would keep asking her until she said "Yes".
  • We cleaned the place until it was spotless.
  • Sometimes we can use before or until to talk about longer situations with little difference of meaning, especially to say how long it is before something happens, or in negatives:
  • I had to wait a week before/until I got an answer.
  • I didn't know anything about her until/before I met her.
  • In positive sentences there is slightly more difference in meaning - before means that the first event was at some indefinite time before, but until stresses that it lasted right up to the time of the second event
  • She worked in a shop before she went to university.
    = at some time before, but not necessarily right up to the time she went to university
  • She worked in a shop until she went to university.
    = more or less right up to the time she went to university
Click and Drop - Where you see this sign, mouse over for instructions

Exercise 1 - complete the sentences with the correct time conjunction or adverbial expression.

after   ·   as   ·   before   ·   by   ·   even as   ·   for as long as   ·   moment   ·   now   ·   once   ·   since   ·   soon   ·   until   ·   when   ·   whenever   ·   while  
1. I see him this afternoon, I'll tell him what you suggested.
2. Let's go for a walk it starts to get dark.
3. They haven't seen each other they got divorced.
4. we had had lunch in a charming little trattoria, we had a look round the cathedral.
5. you're helping the kids with their homework, I'll start making supper.
6. Everyone else had already finished the time we arrived.
7. I think we can start that everyone is here.
8. They've lived in that house I can remember.
9. I won't know the answer I've seen the report.
10. As as you arrive, let us know, and we'll come and collect you.
11. he's in London, he goes to see his grandmother.
12. At the very he said her name, there she was on the doorstep.
13. It's really quite easy you've got the hang of it.
14. Just we turned the corner, an enormous bull wandered out onto the road.
15. And I can see armed police preparing to storm the building, I speak.

Some of these conjunctions can also be prepositions and adverbs

  • Prepositions
  • We'll leave after lunch
  • I need it before tomorrow.
  • They've been here since yesterday.
  • We stayed there until dawn.
  • Adverbs
  • I've never seen him before in my life.
  • They're coming tomorrow or the day after

Tenses in time clauses - 1. talking about the past

To talk about the past we use past tenses in their normal way, but note the use of Past perfect

Use of Past perfect

  • With time conjunctions, especially before, after and as soon as, it's not always necessary to use Past perfect, as the conjunction makes the order of events clear. Especially in spoken English, we tend to use Past simple for both events.
  • After she (had) finished her degree, she got a job in marketing.
  • He (had) found out as much as he could about the company before he went to the interview.
  • As soon as she (had) left, I phoned for a taxi.
  • This happens especially when one event leads directly to the other, or causes the other.
  • When he looked up, he saw a beautiful woman standing in front of him.
  • When I asked him to help me, he immediately stopped what he was doing.
  • But we do use Past Perfect when we want to stress that one thing happened or was completed before the other, especially after when, which can have several meanings
  • He had already closed the door behind him before he realised he didn't have his keys.
  • By the time she finished lunch, it had begun to rain.
  • When he had done the washing up, he went back to the living room.
  • Occasionally we use Past Perfect with before to talk about the completion of an event which started earlier but finished later than the other event.
  • She stormed out of the room before I had even finished what I was saying.
  • the order of events being:
  • 1. I started to say something
  • 2. She stormed out of the room
  • 3. I didn't manage to finish what I was saying

Exercise 2 - use the verbs in the box in Past simple or Past perfect, whichever you think is more appropriate. (the 'correct' answers are my interpretation, and there may be more than one possibility)

check · end · finish · have · iron · lock · read · see · speak · tell · tidy · work
1. After the concert we went to a restaurant for a meal.
2. He couldn't do any more work until he a cup of coffee and a break.
3. Once I the whole report, I began to understand the problem.
4. When he me the news I immediately called my sister.
5. We knew it was the house for us as soon as we it.
6. After he to Peter, he decided to make a few phone calls.
7. He hung up before I trying to explain what the problem was.
8. By the time she qualified, she for several different companies.
9. Before he went out he all the windows.
10. When I up the flat a bit, I went for a long walk.
11. she wouldn't sign the contract until she the small print.
12. When he his shirt he put it on and chose a tie to go with it.

Tenses in time clauses - 2. talking about the present

We can use time clauses in the present to talk about things that are generally true. They can sometimes act a bit like a zero conditional.

Exercise 3 - Complete the sentences by matching the clauses on the left with those on the right.

1. When it's sunny,athe rest is quite easy.
2. I usually stay at the Dorchesterbit reminds me of my student days.
3. Whenever I hear that song,cI like to walk to work.
4. After Mandy has put the kids to bed,dwhile she's doing the ironing.
5. She likes to watch TVewhen I'm in London.
6. Before he cooks something new,funtil you try explaining it to somebody else
7. Once you've learnt the basics,gI usually read them a story.
8. It sounds easyhhe reads the recipe very carefully.

Tenses in time clauses - 3. talking about the future

Sometimes these are called Future time clauses. As in first conditionals, we use a present tense after the conjunction, and a variety of forms expressing the future in the main clause. The most common words used are when, after, before, as soon as. Although not strictly about time, when talking about future time clauses we also usually include the following expressions: unless, in case, as long as

Using Present perfect in future time clauses

Look at these sentences:
  • When you finish your tea you can go out to play.
  • She can watch TV after she does her homework.
  • Once he fills in the form, he should give it to HR.
  • I'll let you know my findings as soon as I complete this report.
In all these sentences the event in the main clause depends on something being completed in the time clause. When this is the case we can use Present perfect instead of Present simple - When you've finished your tea you can go out to play. etc.
Sometimes it's better to use Present perfect when the verb in the time clause doesn't itself suggest completion:
  • As soon as you've had your lunch, you can go out.
  • better than
  • As soon as you have your lunch you can go out.
But we usually only use Present perfect like this to talk about specific events, where the time sequence is important and the result has some relevance to the immediate future. not about general events. For more general conditions or more distant events we use Present simple.
  • After you've taken next week's test, we'll move on to the next unit.
  • All students will move on to the next level as long as they pass next week's test .

Exercise 4 - Underline the correct option(s). There may be more than one correct option. Click on the appropriate options to underline them.

1. Whenever she has / 'll have the chance she likes to visit the gym.
2. When you go to the shops this afternoon, will / could / do you get some potatoes?
3. While you 're doing / 'll do / do the pasta, I'll prepare the salad.
4. You'd better get dressed before your gran will arrive / arrives / has arrived .
5. After I 've finished / finish / 'll finish this, I'll give you a hand with the housework.
6. We won't be able to do anything until Dad will come / comes back from work.
7. You can go out as soon as you 've done / 'll do your homework.
8. We take / 'll take / 're taking some of these biscuits in case we get hungry on the way.
9. Unless she gets / 's getting / 'll get here soon, we'll have to leave without her.
10. As long as you 'll pass / pass / 've passed all your exams, we'll give you a new computer.

Reducing time clauses

After certain conjunctions, we can shorten or reduce a time clause. This is usually done in a more formal style. We should really only do it, however, when the subject of the time clause is the same as the subject of the main clause, otherwise we'll get a dangling modifier.

1. When, while, once with the verb be

Exercise 5 - rewrite the sentences, removing the subject and the verb be, as in the example

0. When you are in Rome, do as the Romans do.
When in Rome, do as the Romans do
1. When she was at university, she met her future husband.
2. While he was in the garden, he noticed there was a cat in the tree.
3. Once she was in the house, she felt a lot happier.

2. When, while, since, before and after with other verbs

In this construction we can remove the subject and replace the finite verb with an -ing participle.
If the verb is in the passive, with after, before, while and since we use being and the past participle (3rd form). With once we use a past participle (3rd form). After when we usually use a past participle, although or being + past participleis also possible.

Exercise 6 - rewrite the sentences, removing the subject and replacing the finite verb with an -ing participle, a past particple or being + past participle, as in the example.

0. While he kissed her goodbye, he slipped a small package into her hand.
While kissing her goodbye, he slipped a small package into her hand.
1. While he was driving home, he saw some deer.
2. After they had finished lunch, they went for a long walk.
3. She made sure everything was finished before she went home.
4. When he visits us, he always brings presents for the children.
5. He has had the same job since he left school.
6. Before he was made redundant, he had never missed a day's work.
7. Once it has been opened, this product should be consumed within three days.
8. When they are taken with alcohol, these pills can cause drowsiness.

3. Omitting the conjunction altogether.

We can leave out the conjunction altogether when one action quickly follows another action or two actions happen simultaneously.
We can also use the construction having + past participle (3rd form) when we want to show that one action happened first.
In these cases, the time clause also often suggests a cause.
In passive time clauses like - When it is mixed with water, pastis goes a cloudy colour. - where when really means if or whenever, we can replace the conjunction and finite verb with a past participle - Mixed with water, pastis goes a cloudy colour.

Exercise 7 - rewrite the sentences, removing the conjunction and the subject, and replacing the finite verb with an -ing or -ed participle, or having + past participle

0. When he heard someone behind him, he turned round to see who it was.
Hearing someone behind him, he turned round to see who it was.
1. When she looked at the clock, she suddenly realised how late it was.
2. While she was waiting for the spaghetti to boil, she started to make the sauce.
3. When she finally discovered the truth, she confronted him immediately.
4. After he had finished answering his emails, he started on his work.
5. When they are baked in the oven, potatoes are the ultimate winter convenience food.
In these cases it is usually better to have the time clause first, or there may be some ambiguity.

4. Using on to mean immediately

We can use the preposition on followed by an -ing form in a non-finite clause instead of immediately or when + finite clause.
  • Active - On hearing the bell for the break, the children rushed out of the class.
    = Immediately /When they heard the bell for the break, the children rushed ...
  • Passive - On being told there were no vacancies, we started to look elsewhere.
    = Immediately / When we were told there were no vacancies, we started ...
Note that the subject of the on clause is the same as the subject of the main clause.
We can also use on with a noun
  • Please collect your keys on arrival
  • On his return he found a letter waiting for him

5. Replacing the time clause altogether. These are sometimes called elliptical clauses

Sometimes we can replace the clause with an adverbial expression:
  • When he was four, he could read quite easily
    At the age of four, he could read quite easily.
  • Before they had lunch, they had some champagne as an aperitif.
    Before lunch, they had some champagne as an aperitif.

What are dangling modifiers?

Look at these examples of each type of reduction we've discussed and answer the questions that follow them.

Exercise 8 - Choose the best answer. Fill the gaps by clicking on the appropriate option (in grey). If you change your mind just repeat the process.

1. When at university, Betty's favourite subjects were Geography and Maths.
Who or what was at university?
Betty - Betty's favourite subjects
2. While driving home, some deer crossed the road in front of Sandy's car.
Who or what was driving home?
some deer - Sandy
3. Waiting for the spaghetti to boil, time seemed to slow down for Peter.
Who or what was waiting for the spaghetti to boil?
time - Peter
4. On hearing the bell for the break, the classroom emptied immediately.
Who or what heard the bell for the break?
the children - the classroom
5. At the age of four, Tommy's mother noticed how quickly he was learning to read.
Who was four?
Tommy's mother - Tommy
All these sentences contain dangling modifiers - that is to say that the subject of the main clause is not the same as the implied subject of the time clause or expression. The time clauses and expressions have no suitable subject in the main clause to attach themselves to, and so are said to be dangling.
Often when this happens the meaning is perfectly clear, but occasionally it can sound a bit strange or even funny. For example in No 2, it might sound as though the deer were driving, or that in No 5, Tommy's mother was only four years old.
And even when the meaning is perfectly clear, they annoy some readers, so it's best to avoid dangling modifiers by making sure that the subject of the main clause is the same as the person or thing reffered to in the reduced clause.

No sooner ... than, hardly / barely / scarcely ... when

There are four expressions we can use to link two clauses when we want to say something happened very soon after another. The verb in the first clause is usually in the past perfect.
Note that these are fixed pairs - no sooner ... than, and hardly / barely / scarcely ... when/before
  1. We had no sooner arrived than we were called for dinner.
  2. She had hardly begun to sing when the audience burst into applause.
  3. He had scarcely sat down when there was a knock at the door.
  4. They had barely started their walk before it began to pour with rain
These are occasionally also referred to as time clauses but notice the difference in construction between these and standard time clauses. They don't start with conjuctions, and the main clause comes immediately after what look like time words.
In a formal or literary style these are sometimes used with negative inversion, for example - No sooner had she finished her lunch than she had to rush off.

Exercise 9 - Make sentences from the four sentences above, using negative inversion, as in the example above.




For this lesson I've relied heavily on:

Related posts


Future time clauses

Reducing time clauses

1 comment:

  1. It was extremely useful for my class today. Thank you for the great work you've done!