Unit 25. When I do / When I've done. When and if.

Unit 25; Part A

Study this example:
'I'll phone you when I get home' is a sentence with two parts:
the main part: 'I'll phone you'
and the when-part: 'when I get home'

The time in the sentence is future ('tomorrow'), but we use a present tense (I get) in the when-part of the sentence.

We do not use will in the when-part of the sentence.

Some more examples:
•    We'll go out when it stops raining. (not when it will stop)
•    When you are in London again, come and see us. (not When you will be)
•    (said to a child) What do you want to be when you grow up? (not will grow)

The same thing happens after while / before / after / as soon as / until or till:
•    I'm going to read a lot while I'm on holiday. (not while I will be)
•    I'll probably go back home on Sunday. Before I go, I'd like to visit the museum.
•    Wait here until (or till) I come back.

Unit 25; Part B

You can also use the present perfect (have done) after when / after / until / as soon as:

•    Can I borrow that book when you've finished with it?
•    Don't say anything while Ian is here. Wait until he has gone.

If you use the present perfect, one thing must be complete before the other (so the two things do not happen together):
•    When I've phoned Kate, we can have dinner.
     (= First I'll phone Kate and after that we can have dinner.)

Do not use the present perfect if the two things happen together:
•    When I phone Kate, I'll ask her about the party. (not When I've phoned)

It is often possible to use either the present simple or the present perfect:

• I'll come as soon as I finish.
• You'll feel better after you have something to eat

or I'll come as soon as I've finished.
or You'll feel better after you've had something to eat.

Unit 25; Part C

After if, we normally use the present simple (if I do / if I see etc.) for the future:

•    It's raining hard. We'll get wet if we go out. (not if we will go)
•    I'll be angry if it happens again. (not if it will happen)
•    Hurry up! If we don't hurry, we'll be late.

Unit 25; Part D

Compare when and if:
We use when for things which are sure to happen:
•    I'm going shopping later. (for sure)   When I go shopping, I'll buy some food.

We use if (not when) for things that will possibly happen:
•    I might go shopping later. (it's possible)    If I go shopping, I'll buy some food.
•    If it is raining this evening, I won't go out. (not When it is raining)
•    Don't worry if I'm late tonight. (not when I'm late)
• If they don't come soon, I'm not going to wait. (not When they don't come)

Exercises

1 Complete the sentences using the verbs in brackets.

Complete the sentences using the verbs in brackets. All the sentences are about the future. Use will / won't or the present simple (I see / he plays / it is etc.).

1    I   'll phone (phone) you when I    get    (get) home from work.
2    I want to see Julia before she _________ (go) out.
3    We're going on holiday tomorrow. I _________ (tell) you all about it when we _________ (come) back.
4    Brian looks very different now. When you _________ (see) him again, you _________ (not/ recognise) him.
5 _________ (you / be) lonely without me while I _________ (be) away?
6    We must do something soon before it _________ (be) too late.
7    I don't want to go without you. I _________ (wait) until you _________ (be) ready.
8    Sue has applied for the job. but she isn't very well-qualified forit. I _________ (be) surprised if she _________ (get) it.
9    I hope to play tennis tomorrow if the weather _________ (be) nice.
10 I'm going out now. If anybody _________ (phone) while I _________ (be) out, can you take a message?

2 Make one sentence from two.

Make one sentence from two.

1    It will stop raining soon. Then we'll go out.
           We'll go out    when   it stops raining.
2    I'll find somewhere to live. Then I'll give you my address.
      I _________________ when _________________
3    I'll do the shopping. Then I'll come straight back home.
      _________________ after _________________
4    It's going to get dark. Let's go home before that.
      _________________ before _________________
5    She must apologise to me first. I won't speak to her until then.
      _________________ until _________________

3 Read the situations and complete the sentences.

Read the situations and complete the sentences.

1    A friend of yours is going on holiday. You want to know what she is going to do.
      You ask: What are you going to do when    you are on holiday   ?
2    A friend of yours is visiting you. She has to go soon but maybe there's time for some more coffee.
      You ask: Would you like some more coffee before ___________________?
3    You want to sell your car. Jim is interested in buying it, but he hasn't decided yet.
      You ask: Can you let me know as soon as ___________________?
4    Your friends are going to New York soon. You want to know where they're going to stay.
      You ask: Where are you going to stay when ___________________?
5    The traffic is very bad in your town, but they are building a new road at the moment.
      You say: I think things will be better when they ___________________.

4 Put in when or if.

Put in when or if.

1    Don't worry    if    I'm late tonight.
2    Tom might phone while I'm out this evening. ______ he does, can you take a message?
3    I'm going to Rome next week. ______ I'm there, I hope to visit a friend of mine.
4    I think Jill will get the job. I'll be very surprised ______ she doesn't get it.
5    I'm going shopping ______ you want anything, I can get it for you.
6    I'm going away for a few days. I'll phone you ______ I get back.
7    I want you to come to the party, but ______ you don't want to come, that's all right.
8    We can eat at home or, ______ you prefer, we can go to a restaurant.

Unit 24 Unit 25 Unit 26