By vs. Until

Difficulty Level: ★ ★ ★ ☆ ☆

Many students struggle with "by" and "until". In this lesson we will learn how to use them correctly when discussing time.

Both, "until" and "by" are used to indicate any time before, but not after a specific time or event. Let's look at until first.


Until is used to show how long a situation will continue for. Until is mostly used before a situation, action (verb), or event will end. Some examples will help us understand:

1.) I work until 5:30 pm every day.

2.) I usually stay up until my homework is finished.

3.) I exercise from 5:00 pm until 6:30 pm everyday.

4.) I want to live with my parents until I get married.

5.) Three months remain until Apple reveals it's next iphone.

6.) The peace talks will continue between Putin and Obama until the end of the week.


By is usually used before, or at a specific time or deadline.

1.) I finish work at 6:30 pm but I usually leave the office by 7:00 pm.

2.) The movie starts at 7:00 pm. Let's get to the theatre by 6:50.

3.) The package will arrive by tomorrow.

4.) I tend to fall asleep by 11:00 pm.

5.) By this time next year I want to be married.


1.) Using "until" in negative sentences is common in English:

The package won't arrive until tomorrow.

I don't want to get married until I have a full time job.

2.) Using "by" is common in English when asking questions:

What time will you finish work by?

What time will the delivery arrive by?

Can we finish the project by this Thursday?

3.) If all this is still confusing for you, just stick to using the preposition "at".


Choose either 'by' or 'until' to fill in the blanks.

  • 1.) What time will the package arrive ___?
  • 2.) The package won't come ___ next Thursday.
  • 3.) We have lots of time. The movie doesn't start ___ 7:00 pm.
  • 4.) Most Koreans live with their family ___ they get a full-time job.
  • 5.) Most Koreans move out ___ the time they get a full-time job.
  • 6.) I go to sleep ___ 1:00 am almost every night.
  • 7.) I stay up ___ 1:00 am almost every night.
  • 8.) Let's work on this ____ 6:00 pm and then go home if we finish.
  • 9.) Let's try to finish and go home __ 6:00 pm.


Try to use 'by' or 'until' in your answer and try answering in full sentences:

1.) How late do you stay up on the weekends?

2.) What time do you usually get home after work?

3.) At what age would you like to have children?

4.) When would you like to retire?

5.) How late do you stay out on the weekends?

6.) How late do you stay up during the week?

7.) If the movie starts at 7:00 pm, what time should we get there?

8.) If the movie starts at 7:00 pm and is about two hours long what time should the movie go on until?

Daily Expressions, Phrasal Verbs & Idioms:

1.)"By the time": Means not later than the time/event mentioned.

"The movie will have already started by the time I get there." "By the time my girlfriend puts her makeup on I'll be an old man."

2.) "Stay up": Means to stay awake.

"I tried to stay up until the sunrise, but I was too tired." "When I was younger I could stay up and drink all night long."

 a collage of pictures related to South Korea.