As long as, provided and in case
You can borrow it as long as you bring it back. Take a coat in case it gets cold: why in case is not if.
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If is not the only word that introduces a condition. As long as and provided (that) mean "only if": the condition must be met. In case is different: it means "because something might happen", and the action is done anyway, before we know.
Word | Meaning |
|---|---|
as long as, so long as | only if, on this condition |
provided, providing | only if (more formal) |
in case | because it might happen |
unless | if not, except if |
As long as: only if
As long as (or so long as) puts a condition on something. Without the condition, the answer is no.
- You can borrow my car as long as you drive carefully.
- I don't mind where we eat, as long as it isn't too expensive.
- As long as you keep the receipt, you can return it.
- Incorrect: You can stay as long as you will be quiet.
- Correct: You can stay as long as you're quiet.As after if, use a present tense for the future.
As long as also has its ordinary meaning of time, "for the whole time that": You can stay as long as you like. The context tells you which one is meant.
Provided and providing: a little more formal
Provided (that) and providing (that) mean the same as as long as. They are common in rules, agreements and careful speech. That can be left out.
- I'll lend you the money, provided you pay me back by June.
- Students may use a dictionary, provided that it is a paper one.
- Providing the weather is good, the concert will be outdoors.
- Incorrect: Provided you will finish the work, you'll be paid on Friday.
- Correct: Provided you finish the work, you'll be paid on Friday.Provided is like if: the present tense refers to the future.
An even more formal phrase is on condition that: They agreed to help on condition that their names were not published.
In case: just to be safe
In case + subject + verb says why you do something now: because something might happen later. You do it whether that thing happens or not.
- Take an umbrella in case it rains.
(It might rain. Take an umbrella now, to be safe.)
- I'll write down the address in case I forget it.
- Keep some cash on you in case the card doesn't work.
- Incorrect: Take my number in case if you get lost.
- Correct: Take my number in case you get lost.In case already contains the meaning of if, so don't add if.
- Incorrect: I'll take a book in case the train will be late.
- Correct: I'll take a book in case the train is late.After in case, use a present tense for the future, as after if.
In case or if?
The two words lead to different actions. Compare:
- I'll buy some juice in case your friends come.
(I'll buy it now. Maybe they'll come, maybe not.)
- I'll buy some juice if your friends come.
(I'll buy it later, and only if they come.)
So when the action is a precaution, taken now before you know what will happen, the word is in case: It's sunny now, but take a jacket in case it gets cold later.
In a story in the past, the verb after in case is in the past: I took a jacket in case it got cold.
In case of + noun
In case of + noun is formal and is mostly seen on signs and in instructions. Here it means "if there is".
- In case of fire, do not use the lift.
- In case of emergency, call 112.
Unless: if not
You met unless at B1. It means "if ... not" or "except if", and it is often close to as long as ... not.
- I'll be there at eight unless the train is late.
(I'll be there if the train isn't late.)
- We'll eat outside unless it's too cold.
- Incorrect: Unless you don't hurry, you'll miss the bus.
- Correct: Unless you hurry, you'll miss the bus.Unless already means "if not", so don't add another not.
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