In this English grammar lesson, we will teach you the difference between the prepositions of time “by” and “until”.
이번 문법 강의에서는 'by'와 'until'을 올바르게 사용하는 방법을 알려드립니다.
When used as a preposition of time, “by” means before a specific time. Or, to put it another way, “by” shows a time limit for something to happen.
If an event must happen before a specific time is reached, then you should use “by”.
Examples:By * Josh will be back from Australia by Tuesday.
* I want to be able to run 10K by April. (i.e. I want to run 10K before April 1st.)
* Please finish your homework by Friday. (i.e. Give me your homework before the end of the day on Friday.)
When used as a preposition of time, “until” describes a continuous action that ceases at a specific time. We use “until” to describe the duration of an action before a specific time or deadline.
Examples:Until * Josh is staying in Seoul until November 1st. (i.e. He will leave on November 1st.)
* I will exercise until 5 p.m. (i.e. I am not going to stop exercising until 5 p.m.)
* You have until 5 p.m. to finish that report. (i.e. Give me the report by 5 p.m at the latest.)
Note: ‘Till’ can be used in place of ‘until’ in informal situations.
Examples:Till * What time are you open till?
* I will be here till tomorrow.
* I will wait here till you return.
Please look at the following examples to get a better understanding of how ‘by’ and ‘until’ differ.
Examples:By/Until * I must leave by 8 p.m. (i.e. I can’t stay later than 8 p.m.)
* I can only stay until 8 p.m. (i.e. I can’t stay later than 8 p.m.)
* I will stay here until 7.30. (i.e. I will leave at 7.30 exactly.)
* I will stay here until at least 7.30. (i.e. I will not leave before 7.30.)
* I will leave here by 7.30. (i.e. I will leave sometime before 7.30 – but close to 7.30.)
Situation: Talking about a report you must do by the Sunday deadline.
* I have until Sunday to finish my research.
* I must finish my research by Sunday.
Situation: Talking about a friend who is leaving the country on November 1st.
* Josh will be in Korea until November 1st.
* Josh will be gone by November 2nd.
* Josh will have left Korea by the 3rd of November. (He is leaving on the 1st.)
* Josh can’t come to your party on the 3rd because he is only in Korea until the 1st.
As a preposition of time, “by” means at or before a specific time. Or, to put it another way, “by” shows a time limit for something to happen. If an event or action must happen at or before a specific time, then you should use “by”.
Communication tip: ‘By’ is often used to indicate a deadline. As in, the event/action can conclude or be done before but not after this time.
Examples: By * You have to finish the course by May 31./ (i.e. May 31 is the last day you can finish the course; you may finish before this date.) * Josh will be back by 7 p.m. / (i.e. Josh might be back before then, but if you come after 7 p.m. he will be here for sure.) * Josh will be back from lunch by midday. * I want to be able to speak English well by Christmas. * Please finish your proposal by Friday. / (i.e. Complete your proposal before the end of the day on Friday.)
When used as a preposition of time, “until” describes a continuous action that ceases at a specific time. In general, we use “until” to describe the duration of an action before a specific time or deadline.
In short, until tells us how long a situation continues. So, if something happens until a particular time, you stop doing it at that time.
Examples:Until * They lived Sydney until December 1st, 2020. / (i.e. They stopped living in Sydney on December 1st, 2020.) * I will be in Korea until Wednesday. / (i.e. I will be back from Korea on Wednesday.) * Josh is staying at home until he feels better. * I will continue dieting until I lose 5kg. * You have until Thursday. to finish that report. (i.e. Give me the report by Thursday. at the latest)
We also use not...until in negative sentences.
Examples:not....until * Details of the sale will not be available until March. / (i.e. March is the earliest you can expect to receive the details of the sale.) * You cannot have ice cream until you finish your vegetables.