The if part can start the sentence (with a comma) or sit in the middle. After if, use the present for the future: if it rains, not if it will rain. if means maybe; when means it will certainly happen.
A if at the start or in the middle
The if part can come first, followed by a comma, or in the middle, with no comma.
In conversation, the if part often stands alone as an answer.
- If we take the train, it'll be quicker.
- If you don't leave now, you'll miss the start.
- If you're thirsty, help yourself to a drink.
- If the doorbell rings, could you get it, please?
- It'll be quicker if we take the train.
- You'll miss the start if you don't leave now.
- I'm going to the match if I can get a ticket.
- Do you mind if I open the window? (= Is it OK if I open it?)
- "Are you coming to the gig?" "Yes, as long as I can get the night off. If I can, I'll be there."
B if + present for the future
After if, use the present, not will: if you see (not if you will see).
- If you see Tom tomorrow, could you ask him to ring me?
- If I'm late tonight, start without me. (not if I will be)
- What shall we do if it snows? (not if it will snow)
- If I don't feel better tomorrow, I'll stay in bed.
C if and when
If I go out = maybe I will go out; I am not sure.
When I go out = I am going out; it is certain.
- "Are you going out later?" "Maybe. If I go out, I'll lock the back door."
- "Are you going out later?" "Yes, I am. When I go out, I'll lock the back door."
- When I get home tonight, I'm going to make a curry.
- If I'm late tonight, start without me. (not When I'm late)
- We'll have the barbecue outside if it stays dry. (not when it stays dry)
Exercises
99.1 Make sentences beginning with If. Join one part from each list. List A: you don't hurry / you pass the test / you fail the test / you don't want this newspaper / you want those posters / you're busy now / you're hungry / you need money. List B: you'll be late / you'll get a certificate / you can take it again / I'll recycle it / you can have them / we can talk later / we can have lunch now / I can lend you some.
If you don't hurry ...
If you don't hurry, you'll be late.
If you don't hurry, you'll be late.
If you pass the test ...
If you pass the test, you'll get a certificate.
If you fail the test ...
If you fail the test, you can take it again.
If you don't want this newspaper ...
If you don't want this newspaper, I'll recycle it.
If you want those posters ...
If you want those posters, you can have them.
If you're busy now ...
If you're busy now, we can talk later.
If you're hungry ...
If you're hungry, we can have lunch now.
If you need money ...
If you need money, I can lend you some.
99.2 Which is right? Choose the correct form for each gap.
If I'm late tonight, start without me. (I'm / I'll be)
If I'm late tonight, start without me.
Will you send me a postcard if I you my address? (give / 'll give)
Will you send me a postcard if I give you my address?
If there a flood, the road will close. (is / will be)
If there is a flood, the road will close.
If I don't see you at lunch, you this evening. (I text / I'll text)
If I don't see you at lunch, I'll text you this evening.
amazed if Sam and Jo engaged. (I'm / I'll be) (get / will get)
I'll be amazed if Sam and Jo get engaged.
to the wedding if you? (Do you go / Will you go) (they invite / they'll invite)
Will you go to the wedding if they invite you?
99.3 Use your own ideas to complete these sentences. The answers below are examples; yours will be different.
I'm going to the match if ...
Example answer: I'm going to the match if I can get a ticket.
If you don't leave now, ...
Example answer: If you don't leave now, you'll be late for work.
I don't want to go for a walk if ...
Example answer: I don't want to go for a walk if it's raining.
If you drink plenty of water today, ...
Example answer: If you drink plenty of water today, you'll feel much better.
Turn the music down if ...
Example answer: Turn the music down if the baby wakes up.
Josh won't pass his driving test if ...
Example answer: Josh won't pass his driving test if he doesn't practise.
If I have time tomorrow, ...
Example answer: If I have time tomorrow, I'll clean the car.
We can have a barbecue tomorrow if ...
Example answer: We can have a barbecue tomorrow if the weather is nice.
99.4 Put in if or when.
ifwhen
If I'm late tonight, start without me.
If I'm late tonight, start without me.
I'm popping to the shop now. I get back, we can have dinner.
I'm popping to the shop now. When I get back, we can have dinner.
I might pop round to Gran's later. I do, do you want a lift?
I might pop round to Gran's later. If I do, do you want a lift?
you don't feel like cooking tonight, we can get a takeaway.
If you don't feel like cooking tonight, we can get a takeaway.
Do you mind I turn the radio on?
Do you mind if I turn the radio on?
Lily is still at school. she leaves school, she wants to train as a nurse.
Lily is still at school. When she leaves school, she wants to train as a nurse.
Shall we go to the beach on Saturday the weather is nice?
Shall we go to the beach on Saturday if the weather is nice?
We're driving to Cornwall on Friday. We haven't booked a campsite; we'll look for one we arrive. Goodness knows where we'll sleep they're all full.
We're driving to Cornwall on Friday. We haven't booked a campsite; we'll look for one when we arrive. Goodness knows where we'll sleep if they're all full.