Other expressions in conditionals – grammar chart
unless (= if not)
We can use unless in conditional sentences to mean ‘if … (not)’.
- I won’t go on holiday unless I save some money.
- = I won’t go on holiday if I don’t save some money.
We use in case to talk about things that we do to be prepared for something that might happen or might be needed in the future.
- I’ll take my umbrella in case it rains. (=because it might rain)
as long as / provided (that) / providing (that) / on condition (that) / only if
We can use the expressions as long as, provided/providing (that), on condition (that), or only if instead of if when we want to emphasise the condition that needs to be present so that something can happen or be done.
- I’ll tell you what really happened as long as you keep the secret.
- I’ll lend you the money provided (that) you pay me back next month.
- They will speak to the press on condition (that) they remain anonymous sources.
- We will invest the money, but only if you can prove that it’s a safe investment.
whether or not
We use whether or not when there are two alternatives and we want to say that something will happen or will be true in any of those two alternatives. Compare:
- I’ll help him if he needs me. (=I will help him only if he needs me.)
- I’ll help him whether or not he needs me. (I will help him if he needs me, and I will help him if he doesn’t need me, too.)
We also use even if with a similar meaning to ‘whether or not’. It is used to emphasize that something will still be true or will happen if another thing happens.
- Even if you apologise, he’ll never forgive you. (=Whether or not you apologise, he’ll never forgive you.)
suppose / supposing
We normally use suppose or supposing at the beginning of a sentence to make someone imagine a situation. It means ‘what would happen if’, or simply ‘if’ (imagining a situation).
- Supposing I got a job, I wouldn’t be able to travel with you next summer.
- Suppose she doesn’t believe you, what would you do then?