You use unless to introduce the only circumstances in which an event you are mentioning will not take place or in which a statement you are making is not true.
Unless you are trying to lose weight to please yourself, it's hard to stay motivated.
We cannot understand disease unless we understand the person who has the disease.
I'm not happy unless I ride or drive every day.
usage note: Do not confuse unless, except, except for, and besides. Unless is used to introduce the only situation in which something will take place or betrue. In the 1940s, unless she wore gloves a woman was not properly dressed... You mustnot give compliments unless you mean them. You cannot use unless to talk about a situation that results from something not happening. Instead youuse if...not. I'll be glad if she doesn't come. You use except to introduce the only things, situations, people, or ideas that a statement doesnot apply to. All of his body relaxed except his right hand... Travelling was impossible, exceptin the cool of the morning. You use except for before something that prevents a statement from being completely true. The classrooms were silent, except for the scratching of pens on paper... I had absolutelyno friends except for Tom. You use besides to introduce extra things in addition to the ones you are mentioning already. Fruit will give you, besides enjoyment, a source of vitamins. However, note that if you talk about 'the only thing' or 'the only person besides' a particular person or thing, besides means the same as 'apart from'. He was the only person besides Gertrude who talked to Guy.
English Easy Learning GrammarAdverbs and adverbialsWhen you want to add information about how, when, where, or to what extent somethinghas happened, you can use an adverbial. Many adverbials are members ... Read more
English Easy Learning GrammarConditional clausesConditional sentences consist of a main clause and a conditional clause (sometimescalled an if-clause). The conditional clause usually begins with if ... Read more
unless in British English
(ʌnˈlɛs)
conjunction
1. (subordinating)
except under the circumstances that; except on the condition that
they'll sell it unless he hears otherwise
preposition
2. rare
except
Word origin
C14: onlesse, from onon + lesseless; compare French à moins que, literally: at less than
unless in American English
(ʌnˈlɛs)
conjunction
1.
in any case other than that; except that; except if
unless it rains, the game will be played
preposition
2.
except; save
nothing can help him, unless a miracle
Word origin
ME onlesse, earlier on lesse that, in lesse that, at less than, for less
Examples of 'unless' in a sentence
unless
So now when you choose a programme, it will automatically do the series unless you choose otherwise.
The Sun (2016)
Fake leather (unless furniture )?
Times, Sunday Times (2016)
Dairy UK is concerned that the problem of oversupply will get much worse unless young people can be persuaded of the benefits of dairy products.
Times, Sunday Times (2016)
But not so much music - unless I get the bug back.
The Sun (2016)
But none of this is of much avail unless top management is willing to make the change.
Peter F. Drucker MANAGEMENT: task, responsibilities, practices (1974)
They have to understand that unless they take this opportunity then strike action will be held.
Times, Sunday Times (2010)
But having the urge is not much use unless you have the flair to go with it.
Times, Sunday Times (2014)
Do not part with your cash unless you fully understand what that is.
Times, Sunday Times (2009)
But a daughter of a carrier mother will not inherit the disease itself unless her father has the disease.
Bee, Helen The Developing Child (7th edn.) (1995)
Lenders allow you to add the arrangement fee to the loan and most do this automatically unless you request otherwise.
Times, Sunday Times (2006)
The trouble is that we cannot interpret them correctly unless we understand what is happening to manufacturing output and productivity.
Times, Sunday Times (2009)
How can they hope to understand unless they sink to their calves in what was solid land a few weeks back?
Times, Sunday Times (2014)
You don't need to take them beyond that unless told otherwise by your doctor.
The Sun (2016)
It doesn't really amount to very much unless you decide it does.
Times, Sunday Times (2012)
Unless you determine otherwise, they will betray you.
Lumsden, Robert 23 Steps to Successful Achievement (1972)
But if there is an issue they can't do much unless you allow them.
The Sun (2016)
Unless otherwise noted, quotations in this section are from this work.
Cameron, Kenneth M Into Africa - a social history of the East African Safari (1989)
And our behaviour doesn't make much sense unless the importance of identity is understood.
Times, Sunday Times (2010)
Unless management understands the demands of its system of production, it cannot truly make work productive.
Peter F. Drucker MANAGEMENT: task, responsibilities, practices (1974)
Explain to them the things that they wouldn't otherwise know unless they did some research.
Christianity Today (2000)
Don't sign anything unless you clearly understand it.
The Sun (2015)
But it won't happen unless we understand exactly how working fathers differ from working mothers.
Times, Sunday Times (2012)
Sunday bells have sounded out across town and country for centuries but will not do so for muchlonger unless new recruits are found.
Times, Sunday Times (2014)
I very much doubt it unless there is big publicity in it for them.
The Sun (2014)
Don't pay this too much heed unless there are other signs her attention is straying away from you.
The Sun (2012)
There is no proper basis for treating an individual and company differently: the law presumes that both have a good reputation unless shown otherwise.
Times, Sunday Times (2013)
Unless otherwise agreed, the deposit will be 10 per cent of the sale price.
Times, Sunday Times (2015)
Otherwise, unless you or your siblings need your share urgently, you could let the law take its course.
Times, Sunday Times (2013)
In other languages
unless
British English: unless /ʌnˈlɛs/ CONJUNCTION
Unless means if the thing you are talking about does not happen.
He says he won't go to the party, unless I go too.