You use conditional clauses to talk about a situation that might possibly happen and to say what its results might be

1   You use conditional clauses to talk about a situation that might possibly happen and to say what its results might be.

You use ‘if’ to mention events and situations that happen often, that may happen in the future, that could have happened in the past but did not happen, or that are unlikely to happen at all.

If the light comes on, the battery is OK.

I'll call you if I need you.

If I had known. I'd have told you.

If she asked me, I'd help her.

2   When you are talking about something that is generally true or happens often, you use a present or present perfect tense in the main clause and the conditional clause.

If they lose weight during an illness, they soon regain it afterwards.

If an advertisement does not tell the truth, the advertiser is committing an offence.

If the baby is crying, it is probably hungry.

If they have lost any money, they report it to me.

Warning: You do not use the present continuous in both clauses. You do not say ‘If they are losing money, they are getting angry.’

3   When you use a conditional clause with a present or present perfect tense, you often use an imperative in the main clause.

Wake me up if you’re worried.

If he has finished, ask him to leave quietly.

If you are very early, don’t expect them to be ready.

4   When you are talking about something which may possibly happen in the future, you use a present or present perfect tense in the conditional clause, and the simple future in the main clause

If I marry Celia, we will need the money.

If you are going to America, you will need a visa.

If he has done the windows, he will want his money.

Warning: You do not normally use ‘will’ in conditional clauses. You do not say ‘If I will see you tomorrow, I will give you the book.’

5   When you are talking about something that you think is unlikely to happen, you use the past simple or past continuous in the conditional clause and ‘would’ in the main clause.

If I had enough money, I would buy the car.

If he was coming, he would ring.

Warning: You do not normally use ‘would’ in conditional clauses. You do not say ‘If I would do it, I would do it like this.’

6   ‘Were’ is sometimes used instead of ‘was’ in the conditional clause, especially after ‘I’.

If I were as big as you, I would kill you.

If I weren’t so busy, I would do it for you.

You often say ‘If I were you’ when you are giving someone advice.

If I were you, I would take the money.

I should keep out of Brendan's way if I were you.

7   When you are talking about something which could have happened in the past but which did not actually happen, you use the past perfect in the conditional clause. In the main clause, you use ‘would have’ and a past participle.

If he had realised that, he would have run away.

I wouldn’t have been so depressed if I had known how common this feeling is.

Warning: You do not use ‘would have’ in the conditional clause. You do not say ‘If I would have seen him, I would have told him.’

Practice

1     Put the verb into the correct form

I

1     You (to speak) better if you (to be) more attentive.

2     If he (to understand) the situation, he (to act) differently.

3     He (to catch) the train if he (to make haste).

4     If I (to be) you, I (to consider) the matter settled.

5     If only he (to be) here, he (can) tell you.

6     If I (to be) in your place, I (to think) as you do.

7     He not (to do) it if you not (to help) him.

8     If he (to be) present, he (may) object.

9     She (to come) to see you if she not (to be tired).

10   If I (to get) the tickets before twelve o'clock, I (to come) straight home.

II

1     I think that if we (to take shelter) under these trees, we not (to get wet).

2     If I (to hesitate) much longer before getting into the water, he not (to let) me swim at all today.

3     If she (to come) earlier, she (to have been able) to see him before he went out.

4     He (to go) for a ride with you, if he (to repair) his bicycle.

5     If a year ago the sailors (to be told) they were to undertake a trip of this sort, they (to be surprised).

6     If he (to be) present, this not (to occur).

7     If the storm not (to rage), the ship (to leave) the harbour last night.

8     If our telephone not (to be) out of order, I (to ring) you up this morning.

9     If you (to come) between two and three yesterday, you (to find) me at home.

10   If I (to have) to carry that heavy box, I (to be) obliged to drop it after five minutes.

11   I not (to go) to sleep over that book if it not (to be) so dull.

12   If I (to know) you (to come), I of course (to stay) at home.

13   If anyone (to say) such a thing to me, I (to feel) hurt.

14   We never (to solve) the riddle, if you not (to put) us on the track.

2     Open the brackets

I

1     If I had known that you were in hospital I (visit) you.

2     If I (know) that you were coming I'd have baked a cake.

3     If you (arrive) ten minutes earlier you would have got a seat.

4     You would have seen my garden at its best if you (be) here last week.

5     I wouldn't have believed it if I (not see) it with my own eyes.

6     I (offer) to help him if I had realised that he was ill.

7     If I (realise) what a bad driver you were I wouldn't have come with you.

8     If I had realised that the traffic lights were red I (stop).

9     The hens (not get) into the house if you had shut the door.

10   If he had known that the river was dangerous lie (not try) to swim across it.

11   If you (speak) more slowly he might have understood you.

12   If lie had known the whole story he not be) so angry.

13   If I (try) again I think that I would have succeeded.

14   You (not get) into trouble if you had obeyed my instructions.

15   If I (be) ready when he called he would have taken me with him.

16   If she had listened to my directions she (not turn) down the wrong street.

17   If you (look) at the engine for a moment you would have seen what was missing.

18   I (take) a taxi if I had realised that it was such a long way.

19   You (save) me a lot of trouble if you had told me where you were going.

20   If you (not sneeze) he wouldn't have known that we were there.

II

1     If I (see) you in the street yesterday, of course I (say) "Good morning."

2     I'm sorry I threw the newspaper away. I (not throw) it away if I (know) you had wanted it.

3     Why didn't you ask me to help you? -Of course I (help) you if you (ask) me to.

4     I'm sorry I couldn't come to the cinema with you last Friday. - I (come) if I (not be) so busy.

5     I (not cleave) the office early yesterday if I (not finish) my work.

3     Match these parts to make conditional sentences.

Example: 1 – j

1     Dan might help you ... a ... if they are enjoying themselves.

2     You are sure to be late ... b ... if I can remember her phone number.

3     You'll enjoy the Jacques Tatty film ... c ... if you miss the bus.

4     They always stay out late ... d ... if you don't want to.

5     They'll understand it all right... e ... if you phone while I'm out.

6     I'll give her a call ... f ... if you explain it to them.

7     Bill will take a message ... g ... if I have the time.

8     I'll do the shopping ... h ... if you don't have a ticket.

9     You can't get in ... i ... if you can understand French.

10   You needn't come to the party ... j ... if you ask him.

4     Complete these sentences by putting the verb in brackets in the right tense.

Example: If you …ask… Liz, she will tell you what to do. (ask)

1     He's going to visit some friends in Athens if he .............................. time. (have)

2     You shouldn't interrupt them if they ............................................... (work)

3     Maria will get you some money if she ............................................. to the bank. (go)

4     I'll have a word with Jack if he ........................................................ at home. (be)

5     Match these parts to make conditional sentences.

Example: 1 – i

1     If I had their address ... a ... it would cost over £650.

2     If you saw her now ... b ... you might earn a bit more money.

3     If I took more exercise … c ... I could probably stay with Michael.

4     If you got a new job … d ... she must have been out at work.

5     If you asked Heather … e ... she would give you a certificate.

6     If I travelled first class … f ... she would probably give you a lift.

7     If it was a little warmer … g ... we could go for a swim.

8     If she didn't answer the phone … h ... I might lose a bit of weight.

9     If you went to the doctor … i ... I could write and ask them.

10   If I stopped off in Ankara … j ... you would hardly recognise her.

Conditional clauses using modals and 'unless' Main points

¨    You can use a modal in a conditional clause.

¨    You use 'unless' to mention an exception to what you are saying.

1   You sometimes use modals in conditional clauses. In the main clause, you can still use a present tense for events that happen often, ‘will’ for events that are quite likely in the future, ‘would’ for an event that is unlikely to happen, and ‘would have’ for events that were possible but did not happen.

If he can’t come, he usually phones me.

If they must have it today, they will have to come back at five o’clock.

If I could only find the time, I’d do it gladly.

If you could have seen him. you would have laughed too.

‘Should’ is sometimes used in conditional clauses to express greater uncertainty.

If any visitors should come, I'll say you aren't here.

2   You can use other modals besides ‘will’, ‘would’ and ‘would have’ in the main clause with their usual meanings.

She might phone me, if she has time.

You could come. if you wanted to.

If he sees you leaving, he may cry.

Note that you can have modals in both clauses: the main clause and the conditional clause.

If he can't come, he will phone.

3   In formal English, if the first verb in a conditional clause is ‘had’, ‘should’, or ‘were’, you can put the verb at the beginning of the clause and omit 'if. For example, instead of saying ‘If he should come. I will tell him you are sick’, it is possible to say ‘Should he come, I will tell him you are sick’.

Should ministers decide to hold an inquiry, we would welcome it.

Were it all true, it would still not excuse their actions.

Had I known. I would not have done it.

4   When you want to mention an exception to what you are saying, you use a conditional clause beginning with ‘unless’.

You will fail your exams. You will fail your exams unless you work harder.

Note that you can often use ‘if...not’ instead of ‘unless’.

You will fail your exams if you do not work harder.

When you use ‘unless’, you use the same tenses that you use with ‘if’.

She spends Sundays in the garden unless the weather is awful.

We usually walk, unless we're going shopping.

He will not let you go unless he is forced to do so.

You wouldn't believe it, unless you saw it.

5   ‘If’ and ‘unless’ are not the only ways of beginning conditional clauses. You can also use ‘as long as’, ‘only if’, ‘provided’, ‘provided that’, ‘providing’, ‘providing that’, or ‘so long as’. These expressions are all used to indicate that one thing only happens or is true if another thing happens or is true.

I will come only if nothing is said to the press.

She was prepared to come, provided that she could bring her daughter.

Providing they remained at a safe distance, we would be all right.

Detergent cannot harm a fabric, so long as it has been properly dissolved.

We were all right as long as we kept our heads down.

Practice

1     Rewrite these sentences as conditionals.

Example: I can’t write to her because I don’t have her address.

I could write to her, if I had her address.

1     I’d like to go abroad but I can’t afford it.

2     I’m not going to buy that car because it's so expensive.

3     We can’t go out because it’s raining.

4     She won’t come to the party because she’s away on holiday.

5     The central heating isn't working so we can’t turn it on.

2     Rewrite these sentences as conditionals.

Example: Unfortunately I didn’t see him, so I couldn’t give him your message.

If I had seen him, I could have given him your message.

1     Unfortunately he didn’t pass his exams or he might have gone to university.

2     He didn’t realise what was happening or he would have run away.

3     Fortunately I didn’t hear what she said or I would have been very angry.

4     They got in because you didn’t lock the door properly.

5     It only happened because you didn’t follow the instructions.

6     Luckily she didn’t find out or she would have been furious.

7     It's lucky we booked a room or we would have had nowhere to stay.

8     It’s a good job we weren’t going any faster or someone could have been killed.

9     He was so tired that he went home at lunchtime.

3     Match the two parts of these conditional sentences.

Example: 1 – g

1     You can borrow the money ...

2     He'll probably get lost. ...

3     Had I known you were coming. ...

4     George says he will come, ...

5     You are not allowed to park in the school,

6     Should he telephone while I'm out, ...

7     Henry Ford said you could have any colour you wanted, ...

8     Fred will be at school next week, …

a ... I would have invited you to lunch.

b ... would you ask him to call back later?

c ... provided he has recovered from his cold.

d ... unless you are a member of staff.

e ... as long as it was black.

f ... provided he can stay overnight.

g ... so long as you promise to pay it back.

h ... unless someone shows him the way.