We use the
The verb in the if-clause is in the present tense; the verb in the main clause is in the Future Simple. It doesn't matter which comes first. There is usually a comma between the two clauses.
- If you try very hard, you'll see the difference.
- John will be late, if you don't lend him your car.
This type of sentence implies that the action is very probable.
Note that the meaning here is present or future, but the main verb in the if-clause is in a present, not future tense.
1 . Possible variations of the basic form
Sometimes instead of if + present + future, we may have:
a) if + present + may/might (possibility)
- If the climate keeps warming, the Arctic might be warm enough for swimming.
b) if + present + may (permission) or can (permission or ability)
- If your documents are in order, you may/can leave at once. (permission)
- If it stops raining, we can go out." (permission or ability)
c) if + present + must, should or any expression of command, request or advice
- if you want to look slim, you must/should eat less meat.
- if you want to look slim, you had better eat less meat.
- if you want to look slim, eat less meat.
d) When if is used to mean as/since, a variety of tenses can be used in the main clause
2. Variations of the if-clause
Instead of if + present tense, we can have:
a) if + present continuous, to indicate a present actions or a future arrangement."
- If you are waiting for a bus (present action), you'd better join the queue.
- If you are looking for Peter, you'll find him upstairs.
- If you're staying for another night (future arrangement), I'll ask the manager to give you a better room.
b) if + present perfect
- if you have finished dinner, I'll ask the waiter for the bill.
- If has written the letter, I'll post it.
- If they haven't seen the museum, we'd better go there today.