How to Use ‘By’ and ‘Until’

One of the many weird quirks in English is our use of “by” and “until.” Many languages have only one word for both of these. One such language is German. My wife is German, and she is very proud of her perfect, accent-free English.

I don’t remember her actual words, but she once said something like:

I have to be at work until 7:00 a.m.

I thought this was odd, as she is a lawyer and it would be very unusual for her to work at night. Does this mean she will work all night long?

I realized her error, and since she had told me to correct her English when I heard a mistake, I told her about it.

She gave me a suspicious look. I suppose I deserved it because the last time I pointed out a “mistake” she had used the word “herb.” She pronounced it, /ˈhəːb/. Puffing up, I corrected her and assured her that as an American and a native English speaker, I could say that it was definitely pronounced, /ˈɚb/.

She instantly pulled out her Oxford Dictionary, and it said:

herb: /ˈhəːb/ (US /ˈɚb/).

She gloats about that to this day, and insists upon saying /ˈhəːb/ whenever I’m in earshot.

It’s understandable why I got “the look” when now I tried to correct her.

My dear, I’m sure you mean, ‘I have to be at work by 7:00 a.m.’

She was very suspicious, and spent two days researching my correction. She couldn’t believe it. She had gone through many years of English at school, and not once did one of her local German English teachers explain the difference between “by” and “until.” She spoke to her German friends and they hadn’t ever been taught about “by”, either. In German there is only one word, “bis,” that is used in both cases.

Not with English.

When we use “until” like my wife did, it means we have to do something continuously, and we get to stop when we reach the time given. “I have to be at work until 6:00 p.m.” means that no matter what time she started working, she must do it until 6:00 p.m., and then she can go home.

When we use “by” we mean that we have to complete the stated task no later than the time given. “I have to be at work by 6:00 p.m.” means that she must get in her car, drive to the office, walk in the door and punch in at some point at or before 6:00 p.m.

Look at these “by” examples:

  • I must clean the house by the time my wife gets home.
  • We have to write a paper by Monday.
  • They need to cancel the contract by the end of the year.

And these “until” examples:

  • You can play outside until dark.
  • She will shop until she runs out of money.
  • I will be on vacation from December 21st until January 7th.

Practice using “by” and “until,” with my free worksheet.

Can you think of another way to use “by” or “until?” Please leave a comment below.


quirk /ˈkwɚk/: unusual behavior.

assured ˈʃuɚd/: to be sure – certain to be.

to gloat /ˈgloʊt/: to be overly happy that one is right, or to take pleasure in someone else being wrong.

in earshot: to be within hearing distance – near enough to hear what is said.

to punch in: to log in with a paper or electronic clock that tracks one’s work hours. Also: to clock in.

9 thoughts on “How to Use ‘By’ and ‘Until’

      1. Great lesson, Brian. “By” the way, I like your style. “Until” now, I didn’t know you were so interesting. Just kidding. I always knew you had many talents. After all, you are a kin to me.😁

    1. Thanks, Isabeau! I have no idea if most Germans don’t really learn ‘by’ and ‘until’ properly, but according to my wife they don’t. Is there a similar example in French?

  1. This is a fantastic way to teach new things! Even though I thought I knew the differences between those two words, I learnt new things. I would like to have an English teacher at home as well so I could learn new things and be corrected too. My father, who is a journalist, always corrects me when I am talking Spanish and I made a mistake and that has helped me to improve my wrting and also to increase my range of vocabulary.
    In conclusion, I think that the story helps people to learn the use of by and until easily. Keep going Brian!

    1. Haha! Thanks for the nice comment, Sergio! Believe it or not, my German wife corrects my English far more than I ever get to correct hers. I think part of it is she learned grammar properly from the start. As a native speaker, I learned English from friends and family while growing up. Therefore, I am always saying things like, “should have went,” and I’m corrected to say, “should have gone.” These little things make things interesting, but it can be difficult when you are learning English. There are countless examples in pop music, for example, where the lyrics are incorrect grammar.


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