Adults|Grammar|Intermediate|18. Conditional I

— Will you phone me tomorrow? — Yes, I’ll phone you when I get home from work.

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:

1. We’ll go out when it stops raining. (not when it will stop)

2. When you are in London again, come and see us. (not When you will be)

3. (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:

1. I’m going to read a lot while I’m on holiday. (not while I will be)

2. I’ll probably go back home on Sunday. Before I go, I’d like to visit the museum.

3. Wait here until (or till) I come back.

Read the rules

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

1. Can I borrow that book when you’ve finished with it?

2. 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:

1. I’ll come as soon as I finish.

or I’ll come as soon as I’ve finished.

2. You’ll feel better after you have something to eat.

or You’ll feel better after you’ve had something to eat.

Read the rules

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

1. It’s raining hard. We’ll get wet if we go out. (not if we will go)

2. I’ll be angry if it happens again. (not if it will happen)

3. Hurry up! If we don’t hurry, we’ll be late.

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:

1. I might go shopping later. (it’s possible) If I go shopping, I’ll buy some food.

2. If it is raining this evening, I won’t go out. (not When it is raining)

3. Don’t worry if I’m late tonight. (not when I’m late)

4. If they don’t come soon, I’m not going to wait. (not When they don’t come)


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.).


Make one sentence from two


Click on the unnecessary word in the sentences.

Choose when or if

If you open the lesson plan you will be able to assign separate pages as homework or all the homework pages at once.

Урок Homework Курс
  • The example
  • Have done
  • If I do / if I see
  • Will / won't
  • It will stop raining soon
  • Mark the unnecessary word
  • Choose when or if
  • Homework
  1. 1. Adults|Grammar|Intermediate|1. I am doing and I do
  2. 2. Adults|Grammar|Intermediate|2. I am doing and I do
  3. 3. Adults|Grammar|Intermediate|3. I did
  4. 4. Adults|Grammar|Intermediate|4. I was doing
  5. 5. Adults|Grammar|Intermediate|5. I have done
  6. 6. Adults|Grammar|Intermediate|6. I have done 2
  7. 7. Adults|Grammar|Intermediate|7. I have been doing
  8. 8. Adults|Grammar|Intermediate|8. I've been doing / I've done
  9. 9. Adults|Grammar|Intermediate|9. How long have you (been)...?
  10. 10. Adults|Grammar|Intermediate|10. For/since; When/How long?
  11. 11. Adults|Grammar|Intermediate|11. I have done and I did
  12. 12. Adults|Grammar|Intermediate|12. I have done and I did 2
  13. 13. Adults|Grammar|Intermediate|13. I had done
  14. 14. Adults|Grammar|Intermediate|14. I had been doing
  15. 15. Adults|Grammar|Intermediate|15. The future: I am doing / I do
  16. 16. Adults|Grammar|Intermediate|16. I will and I'm going to
  17. 17. Adults|Grammar|Intermediate|17. Future: Continuous/Perfect
  18. 18. Adults|Grammar|Intermediate|18. Conditional I
  19. 19. Adults|Grammar|Intermediate|19. Can, could and (be) able to
  20. 20. Adults|Grammar|Intermediate|20. Have to and must
  21. 21. Adults|Grammar|Intermediate|21. If I do... and If I did...
  22. 22. Adults|Grammar|Intermediate|22. If I knew... I wish I knew...
  23. 23. Adults|Grammar|Intermediate|23. Conditional III
  24. 24. Adults|Grammar|Intermediate|24. Wish
  25. 25. Adults|Grammar|Intermediate|25. Is done / was done
  26. 26. Adults|Grammar|Intermediate|26. Be/been/being + done
  27. 27. Adults|Grammar|Intermediate|27. Passive 3
  28. 28. Adults|Grammar|Intermediate|28. Passive: He is said to...
  29. 29. Adults|Grammar|Intermediate|29. Have something done
  30. 30. Adults|Grammar|Intermediate|30. He said that...
  31. 31. Adults|Grammar|Intermediate|31. Say and Tell
  32. 32. Adults|Grammar|Intermediate|32. Do you know where..?
  33. 33. Adults|Grammar|Intermediate|33. Auxiliary verbs; so/neither
  34. 34. Adults|Grammar|Intermediate|34. Do you? Isn't it? etc.
  35. 35. Adults|Grammar|Intermediate|35. Gerund
  36. 36. Adults|Grammar|Intermediate|36. Verb + to Infinitive
  37. 37. Adults|Grammar|Intermediate|37. Verb + Object + to Infinitive
  38. 38. Adults|Grammar|Intermediate|38. -ing or to: change in meaning
  39. 39. Adults|Grammar|Intermediate|39. Try/Need/Help: -ing or to
  40. 40. Adults|Grammar|Intermediate|40. Like / Would like: -ing or to
  41. 41. Adults|Grammar|Intermediate|41. Some/any/no/none
  42. 42. Adults|Grammar|Intermediate|42. Much/many/few/little
  43. 43. Adults|Grammar|Intermediate|43. Both/either/neither/all/every