Difference Between Until and Unless

Edited by Diffzy | Updated on: May 13, 2023


Difference Between Until and Unless

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In the English language, several words almost seem similar and confusing to people while speaking, Until and Unless are two of them. It can be because of inadequate knowledge of the two words' usage and meaning by the individual. Since they both express different meanings, we cannot use these terms interchangeably in a sentence. We generally use ‘Unless’ and ‘Until’ as a conjunction to connect the sentences, but in some exceptional cases, they can also be used as prepositions. A conjunction is a word that is used to connect two different words, phrases, sentences, or clauses. ‘Until’ and ‘Unless’ comes under the category of subordinating conjunctions and are usually used in conditional situations.

‘Until’ is used as both a preposition and a conjunction, it is used in the constraint of time or to describe a specific time, the word until often denotes before and up until that point in time.

‘Unless’ is used as a conjunction to connect sentences, it is usually used to describe a condition that is not being met. When we claim something will happen or won't happen unless a specific condition is met, we use the word "unless."

Until vs. Unless

The key difference between the words ‘Until’ and ‘Unless’ is that the former is used in the context of time. It refers to the period before a particular event or happening. Whereas, the latter is used to describe a precondition or something is not done unless a condition is met. ‘Unless’ is used just as a conjunction to connect two sentences while ‘Until’ can be used as both a preposition as well as a conjunction.

Until ex-Wait here until I return.

Unless ex- Can you turn off the television unless you are watching it?

Difference Between Until and Unless in Tabular Form

Parameters of comparisonUntilUnless
DefinitionUntil is used to describe a condition related to a specific time. Up to the time of something happening.Unless is used to describe a precondition. It usually means that a condition is not met.
Part of SpeechIt can be used as both a preposition and a conjunction.It is only used as a conjunction to connect sentences.
Conditional InferenceIt establishes time-specified conditions for a task to be done.It sets a condition to choose events over one another.
IndicatesIt highlights the time before an event that is expected to occur.It depicts the only condition in which the mentioned event won't take place.
ExamplesI will do the work until it gets finished.Reema has gone to her grandmother’s house until March.We will wait for her until she comes.You won’t pass the exams unless you study hard with concentration.I don’t text unless it is something important.Be here until I come back.

What does the word ‘Until’ mean?

The phrase "until" signifies up to a specified time or incident. It serves as an indicator of how long a situation has persisted in sentences. It is used to describe circumstances that are time-constrained, and conditions before and up to the time something happened. You can use this expression to provide deadlines for a specific time frame. It is used as both prepositions as well as a conjunction. It is not only used to connect two sentences but also as a preposition that conveys the relationship between a noun or pronoun and a clause element. It also indicates the duration of a situation in a sentence.

How and when to use ‘Until’

It is used as a preposition to describe a specific time limit.

For Ex- Riya watches TV until 3 am

             My friends are on a trip until next weekend.

             The radio broadcasts my favorite show until 4 pm only.

It is also used as a conjunction to establish a connection with a certain moment or place in time with an event.

For Ex- No one can leave the room until the meeting is over.

            We can’t vote until we are 18.

            He stayed with me until I recovered.

To describe the duration of a situation.

For Ex- I studied until 7 am yesterday.

            We are going on a school trip until next week.

            I slept yesterday until noon. 

It is considered a negative form of connection; thus, we should avoid using ‘not’ with ‘until’.

For Ex- Until I finish listening to this podcast, don’t press the pause button.

             Don’t open the door until I return.

             Until I finish reading this book, don’t turn off the lights.

While both ‘until’ and ‘till’ have the same meaning, till is more frequently used in informal writing than in formal writing contexts. While ‘until’ is used in formal writing.

For Ex- Please wait here until they call you.

             I will wait till I hear from you.

             Brent did not arrive until the presentation was almost over.

When referring to a starting or ending point, the words until or till are used.

For Ex- I played tennis from 5 pm until 9 pm.

            The flights are canceled from tomorrow until next the two weeks.

            The trains are scheduled from 3 pm until 9 pm.      


  • The meeting went on until late at night.
  • Ruby lived with her brother until she was 18.
  • Please wait until the next metro arrives.
  • I read a book until I fall asleep.
  • Until someone comes to pick you up, wait here.

What does the word ‘Unless’ mean?

We use the word ‘unless’ to introduce certain conditions. When a condition is met, we use the word "unless" to indicate whether something will or won't happen. The term "unless" indicates a condition before the provided statement may be true; it signifies the condition of ‘except if’. It is used as a conjunction to connect two or more different sentences and introduce conditional clauses. A present, past, or past perfect tense follows ‘unless’ in a sentence.

How and when to use ‘Unless’

When you have to choose a certain condition over another.

For Ex- Unless you wear that dress, you’ll not know it’s fitting.

             You cannot wear that hat unless you wash it.

             Whether the shoes are of your size or not, you’ll not know unless  

              you try it.

When a particular circumstance makes something possible or actual.

For Ex- Unless you finish this project, you can’t play.

             You cannot score unless you work hard.

             You cannot eat your favorite ice cream unless you finish your work.

To describe the conditions, which might not be possible, to mention.

For Ex- She cannot drive unless she has a driver’s license.

             Unless the thunder stops, I cannot go out.

             I cannot drive this bike unless the tires are in good condition.

To describe something- possible only in a specific condition only.

For Ex- You won’t be able to get admission to a good university unless you   

             have scored good grades in school.

             We can’t help unless you tell us the real problem.

We don’t use negative words while we are using unless, in a sentence, it is only followed by positive word forms. We can’t say phrases like:

Unless not, unless no, etc.

We also can’t use it unless followed by ‘will’.

Don’t write:

Unless I will

The words ‘if’ and ‘unless’ are very similar and sometimes can be used in a similar sense in a sentence.

For Ex- He cannot play the piano unless he completes his assignment on time.

If we replace ‘unless’ with ‘if’ in this, it’ll look like:

If he completes his assignment on time, he can play the piano.

If we use ‘if’ in the sentence, it provides a positive sense to the sentence instead of a negative one.

Thus, even though we use ‘if’ and ‘unless’ in two different or opposite aspects, they express the same meaning in a sentence.

Using unless with the present tense.

For Ex- Unless you study properly, you will never understand chemistry.

             Unless you focus on your work, you will never succeed.

Using unless with past tense.

For Ex- She would have reached here an hour ago unless she was stuck in


             He would have attended the meeting on time unless he was late.

Using unless with past perfect tense.

For Ex- I wouldn’t have taken Shelly unless her scooter hadn’t broken down.

             I wouldn’t have purchased these shoes unless they were on sale.


  • We won’t work unless they give us a respectable salary.
  • People won’t trust you unless you give them a reason to.
  • He’ll not visit your home unless you invite him.
  • You will fail in the interview unless you prepare for it well.
  • I will reach London tomorrow unless there are no delayed flights.
  • She won’t go to her house unless you give her a toy.
  • I won’t call you unless it’s something important.
  • You won’t learn unless you make mistakes.
  • We should call a doctor unless she is feeling fine.
  • The court threatened the media unless they stop spreading false rumors about the victim.

In some cases, we can use both terms in a single sentence also, like ‘unless and until’. Because the terms "unless and until" are frequently used together, many people mistakenly believe that they have the same meaning. However, this term should be applied when the circumstance requires both a prior condition and a context of time.

For Ex- I can’t start working unless and until I get proper instructions from the department.

I can’t pay you back the money I lent from you unless and until you give me your bank account details.

Rony’s father told him that he will not get his favorite bike unless and until he scores well in his upcoming examinations.

Main differences between Until and Unless (in points)

  • The word ‘until’ is used to describe a condition up to a certain point in time, up to a specific time when anything must occur. ‘Unless’ is used for preconditions or a condition that is not being met.
  • ‘Until’ is used as a preposition that describes the noun, pronoun, or element in a sentence and as well as a conjunction, but ‘unless’ is only used as a conjunction to link sentences.
  • The word unless is used to introduce a condition under which the occurrence being discussed is possible. On the other hand, until can be used to emphasize the time that comes before the event occurs.
  • ‘Until’ talks about the restriction of time whereas ‘Unless’ talks about the dependency of conditions on one another in a sentence, while they are connected through the conjunction “unless”.
  • Until examples- We will wait until the next flight arrives.

                           He is usually at home until 9 am.

                           I will wait until I hear from my boss.

  • Unless example- She won’t get healthy unless she changes her lifestyle.

                             Nobody will know your ideas unless you express them.

                             I am going unless you want to come too.


Although it can be challenging at times to recall these grammatical principles, doing so is necessary if you want to be a competent learner of this language. This article provided an overview of the fundamental definitions of "until" and "unless," the main distinctions between the two, when to use them according to the sentence structure, and several examples to help readers better comprehend the idea and usage of these grammatical terms.

Understanding what they imply, such as that while unless means except that, until means before that, is a great method to remember the difference between the words. In summary, until specifies the time limit for the incident to happen whereas unless indicates an exception to the provided statement.

The main key difference to memorize is that ‘until’ is used to depict a condition that is based on a specific time limit whereas ‘unless’ refers to a condition that is not being met or after something has taken place. We can use ‘until’ as both a preposition and a conjunction but the limitation here is ‘unless’ can be used only as a conjunction in a sentence that serves the purpose of connecting two distinct phrases into a meaningful sentence.


  • https://www.englishlessonviaskype.com/difference-between-unless-and-until/
  • https://english.eagetutor.com/spoken-english-grammar/unless-and-until-learn-the-difference
  • https://www.bbc.co.uk/worldservice/learningenglish/grammar/learnit/learnitv338.shtml
  • https://assignmentpoint.com/difference-between-unless-and-until/


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"Difference Between Until and Unless." Diffzy.com, 2024. Thu. 29 Feb. 2024. <https://www.diffzy.com/article/difference-between-until-and-unless-1318>.

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