Unless, As Long As, and Provided
A complete C1 guide to unless, as long as, so long as, provided, and providing — how they express conditions, the difference from if, and the present tense rule for future conditions.
Unless
unless means except if or only if … not.
You cannot go in unless you are a member.
(= except if you are a member / only if you are a member)
I will see you tomorrow unless I have to work late.
(= except if I have to work late)
There are no buses to the beach. Unless you have a car, it is difficult to get there.
(= except if you have a car)
You can often use if ... not instead of unless.
Unless we leave now, we will be late.
= If we do not leave now, we will be late.
But unless is not exactly the same as if ... not. Use unless for except if situations.
As Long As / So Long As
as long as and so long as mean if or on condition that.
You can borrow my car as long as you promise not to drive too fast.
(= You can borrow it, but only on the condition that you drive carefully.)
I do not mind if you come home late as long as you come in quietly.
These expressions focus on the condition that must be true for something to happen.
Provided / Providing
provided (that) and providing (that) also mean if or on condition that. They are slightly more formal than as long as.
Travelling by car is convenient provided (that) you have somewhere to park.
(= It is convenient, but only if you have parking.)
Provided (that) the room is clean, I do not mind which hotel we stay at.
You can use that after provided and providing, but it is optional.
| Expression | Formality |
|---|---|
as long as | neutral |
so long as | neutral |
provided (that) | slightly formal |
providing (that) | slightly formal |
No Will After These Words
When talking about the future, do not use will after unless, as long as, so long as, provided, or providing. Use the present tense.
| Correct | Incorrect |
|---|---|
I am not going out unless it stops raining. | |
Providing the weather is good, we will have a picnic. | |
You can borrow it as long as you promise not to drive fast. |
Common Mistakes
| Mistake | Better | Why |
|---|---|---|
| I won’t go unless it will stop raining. | I won’t go unless it stops raining. | Do not use will after unless. |
| As long as you will be careful, you can use it. | As long as you are careful, you can use it. | Use present tense, not will, for future conditions. |
| Unless you don’t have a ticket, you can’t enter. | Unless you have a ticket, you can’t enter. | unless already contains a negative idea. Do not add another negative. |
Practice: Exercises
You won't pass the exam ___ you try a bit harder.
Summary
unless means except if. It is often similar to if ... not, but not exactly the same.
as long as and so long as mean if or on condition that.
provided (that) and providing (that) are slightly more formal ways to say on condition that.
Do not use will after unless, as long as, so long as, provided, or providing when talking about the future. Use the present tense instead.