Practice
Unless: state an exception or condition
Sign in to saveUnless the bus is late, we will arrive before the meeting starts. Unless tells you the one condition that could change the result.
Use unless to state the condition that would stop, change, or allow a result, and choose the verb form that fits the time and meaning.
Read and practice
Read the examples and try the written questions in this guide. Listening recordings are not available for this lesson yet.
Try the written questions
Unless the rain stops, we'll wait inside. /ənˈles ðə reɪn stɒps wiːl weɪt ɪnˈsaɪd/
The short answer
Use unless to mean if not when one condition changes a result. Say, Unless the road is closed, we will take the usual route. The usual route is the plan, and a road closure is the exception.
Unless the train is delayed, it will arrive before eight.
Why it works: The train is expected to arrive before eight. A delay is the condition that could change that result.
5 more examples
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I will not sign the form unless I understand every part.
Understanding the form is the condition for signing it.
Not this:I will not sign the form
unless I do not understandevery part. What changes: Do not add not when unless already means if not. This changes the intended condition. -
Unless we leave now, we will miss the first bus.
Leaving now is necessary if the group wants to catch the first bus.
Not this:Unless
we will leavenow, we will miss the first bus. What changes: For a future condition, use the present form leave after unless, not will leave. -
The office is closed unless you have an appointment.
Having an appointment is the exception to the usual rule that the office is closed.
Not this:The office is closed
if you have an appointment. What changes: If changes the meaning here. It says an appointment causes the office to be closed. -
Unless Maya calls by noon, I will send the details by email.
A call by noon would change the speaker's plan to send an email.
Not this:I will send the details by email
unless Maya calls by noon. What changes: The meaning stays the same when the unless clause comes second. -
You cannot enter unless you show a ticket.
Showing a ticket is necessary before entry is possible.
Not this:You can enter
unless you show a ticket. What changes: Changing cannot to can reverses the rule and gives an unlikely meaning.
Read the full guide
First, decide which fact would change the result. Put that fact after unless. In a future condition, use a present form after unless, even when the other clause uses will. Then check whether if not gives the same meaning. If it does, unless may be the clear choice.
Find the condition that changes the result
Start with the result you expect. Then ask what could stop it or make it different. That fact belongs after unless. In a travel plan, a delayed train can change an expected arrival time.
Unless the train is delayed, it will arrive before eight.
The expected result is an arrival before eight. A delay is the one condition that could change it.
A meeting will begin on time if the presenter arrives. Which condition can you put after unless?
Say, Unless the presenter arrives, the meeting will not begin on time. The presenter's arrival changes the result.
Check whether if not has the same meaning
Unless often means if not. This check can help you choose the right connector. Replace unless with if not and read the full sentence again. If the result stays the same, unless is possible.
Unless the road is closed, we will take the usual route.
This means, If the road is not closed, we will take the usual route. Both sentences name a road closure as the exception.
Does unless work in this idea: If the file is not saved, the changes disappear?
Yes. You can say, Unless the file is saved, the changes disappear. The meaning stays close to if the file is not saved.
Do not add another not
Unless already gives the idea of if not. For that reason, an extra not usually changes the meaning or makes the sentence hard to follow. Keep the verb after unless positive when you mean if something does not happen.
I will not sign the form unless I understand every part.
Understanding every part is the condition for signing. The sentence means the speaker will not sign if they do not understand the form.
Choose the clearer ending: unless she calls or unless she does not call.
Use unless she calls when you mean if she does not call. Unless already carries that negative condition.
Use a present form for a future condition
An unless clause can describe a future possibility, but English usually uses a present form there. Put will in the result clause when you need it. This pattern is common in plans, warnings, and arrangements.
Unless we leave now, we will miss the first bus.
Leave is present in the unless clause, while will miss shows the future result.
Complete the condition: Unless the package ____ today, I will contact the store.
Use arrives: Unless the package arrives today, I will contact the store. Use the present form after unless.
Use unless for rules and exceptions
Rules often have one exception. Unless can state that exception in a short, direct way. Read the main clause first to find the usual rule, then read the unless clause to find who or what is different.
The office is closed unless you have an appointment.
The usual situation is that the office is closed. An appointment is the exception.
You cannot enter unless you show a ticket.
The rule blocks entry. Showing a ticket is the condition that allows entry.
State the exception to this rule: Guests cannot use the pool when a staff member is absent.
Say, Guests cannot use the pool unless a staff member is present. A staff member's presence is the exception.
Place the unless clause clearly
You can start with the condition or put it after the result. Starting with unless often puts the warning or exception first. Use a comma after the first clause. When the unless clause comes second, you do not usually need a comma.
Unless Maya calls by noon, I will send the details by email.
The comma separates the opening condition from the result.
I will send the details by email unless Maya calls by noon.
The same condition comes second, so the sentence usually has no comma before unless.
Where can you put unless in a sentence about leaving early because the weather may change?
Either position works: Unless the weather improves, we will leave early. Or, We will leave early unless the weather improves.
Before you go
Remember this
Use unless for the condition that changes a result. It often means if not, so do not usually add another not after it. In future sentences, use a present form after unless: Unless we leave now, we will miss the bus. Put a comma after the unless clause when it comes first.
Practice with the written examples
You can practice with the written questions in the Learn tab. Each answer includes an explanation.
Try the written questionsListening test not available yet
This lesson does not have the recordings needed for a listening test. Use the written questions in the guide to check your understanding.
Try the written questionsQuestions about "Unless: state an exception or condition"
What does unless mean?
Unless usually means if not. It introduces the condition that would stop or change a result. In the sentence Unless the train is delayed, it will arrive before eight, a delay is the one event that could change the expected arrival time.
Unless the train is delayed, it will arrive before eight.
Can I use not after unless?
Usually, no. Unless already has the meaning of if not, so an extra not can reverse the meaning. Say I will not sign the form unless I understand every part when understanding the form is required before signing.
If the train is not delayed, it will arrive before eight.
Do I use will after unless?
Use a present form after unless for a future condition. Say Unless we leave now, we will miss the first bus. The result clause can use will, but the unless clause normally uses leave, arrive, call, or another present form.
I will not sign the form unless I understand every part.
Can an unless clause come at the end of a sentence?
Yes. You can put the result first and the condition second: I will send the details by email unless Maya calls by noon. When the unless clause comes first, use a comma after it.
I will not sign the form unless I do not understand every part.
When is unless useful for a rule?
Use unless when a rule has a clear exception or requirement. The office is closed unless you have an appointment means that an appointment is the exception. The main clause gives the usual rule, and the unless clause names what changes it.
Unless we leave now, we will miss the first bus.