In some languages such as my native languages (Kurdish and Persian), when we want to ask about the exact limit point of time for something, we use two words which are exactly equal to this two words in English: Until When?

For example, we say: Until when do I have time to finish this project?

I would like to know how much this way of asking is natural in different English speaking countries? Or if it sounds pretty weird to you, please tell me how you say the above sentence in English.


I think the “until when” construct can work fine in a question like this, although I think I’d be inclined to change the order of the words:

I have until when to finish this project?

Also, it’s worth noting that we will often put additional emphasis on the word when in such questions, particularly when expressing surprise. For example:

Ted: I’ll need this project done by Friday.
Ned: I have until when to finish this project?

In this dialogue, Ned isn’t really asking Ted for a deadline; he is expressing incredulity that the deadline is coming so soon. In other words, Ned knows the project needs to be done by Friday, but he is astonished that he has so little time to accomplish so much work.

Of course, there are many other ways people can ask about an upcoming deadline. I especially like the suggestions provided by Bob Jarvis and Ronnie Childs elsewhere in answers and comments under this question:

  • When is the deadline for this project?
  • How long do I have to finish this project?
  • 2
    Another way of asking the question would be "How long do I have to finish the project?" and I would expect a time period, like "2 weeks". If I ask "I have until when..." I would expect a date or day, like "March 26th"
    – ColleenV
    Mar 10 '19 at 12:54
  • 5
    I think "When is this due?" is being overlooked as a concise alternative. Mar 11 '19 at 17:46

There are certainly sentences where it would sound entirely appropriate.

Boss: Keep working on this.
Employee: Until when?

Parent: You are grounded!
Child: Until when?

Both usages are complete sentences. Used as part of a sentence sounds a bit more strained and unnatural.

  • 2
    The words "until when" do not gramatically constitute a complete sentence, because a sentence must have a verb. In casual conversation, however, such questions imply the previous statement to become complete: "Until when (am I grounded)" Mar 11 '19 at 17:09

Until when is occasionally used but not nearly as often as just when or by when.

So most common are:

When do I have to finish this project
By when do I have to finish this project.

But these two constructions don't necessarily mean the same thing.

The first is ambiguous; it can be understood either as at what time/on what day do I have to finish it - or by when do I have to finish it.

The second means by when must it be completed - by what time, day or other period.

People also ask:

What is the deadline for completion

So my recommendation is that you stick to: By when does it have to be completed.

Here is a related Ngram, comparing the use of by when and until when.

  • I would like just out of pure personal curiosity, would you completely "discard" to use the "Until when"? Even though it is grammatically correct?
    – user17814
    Mar 10 '19 at 11:40
  • 1
    Not at all. Depending on the context, I might well use it, as J.R. illustrates. Mar 10 '19 at 11:51

Until when is not a particularly common construct in this situation. You would be more likely to hear How long, as in:

How long do I have to finish this assignment?

  • This is the only answer that explicitly answers the 'does it sound natural' part of the question. The answer to that is (as this answer correctly states), in the context of the question: 'no, it does not sound natural'. It only sounds natural if you put a different spin on the original question. Mar 11 '19 at 14:36

Not a native, but I think natives would most commonly use

How much time do I have to finish this project?

However, I believe

Until when do I have to finish this project?

Might be grammatically sound. Now I am not entirely sure whether a native would use that or not

  • 1
    As a footnote, this native speaker would have no problem using that.
    – J.R.
    Mar 10 '19 at 11:11
  • As a native without any restriction of using "until when", what would you instinctively say??
    – eefar
    Mar 10 '19 at 12:38
  • 9
    @eefar As a native British English speaker, I would never say "until when" unless I was deliberately using an unusual choice of words or grammar for some reason. "Until when do I have do finish" is confusing. "Until Thursday" (for example) means "the interval of time start now and ending on Thursday." You don't finish a project during an interval of time, you finish it at a moment in time. A better sentence would be just "When do I have to finish this project?" or "By when..." (or less formally, "When do I have to finish this project by?")not "Until when..."
    – alephzero
    Mar 10 '19 at 13:24
  • @alephzero Fully agree. "Until when do I have to stand here?" makes perfect sense, as it's asking about a duration; "Until when do I have to finish this project" doesn't, because the response "You have to finish it until Thursday" doesn't make sense. Mar 10 '19 at 17:37
  • @DavidRicherby "You have until Thursday to finish it." makes perfect sense, and is the answer I'd expect if somebody asked "Until when do I have to finish this?" Unlike your "stand here" example, that doesn't mean you have to spend every moment between now and Thursday "finishing" it; it just means that at some point between now and Thursday, it has to be finished. The "Until when..." wording wouldn't be my first choice, but it doesn't seem particularly problematic to me. Mar 11 '19 at 14:53

(Note: This is from a Northeastern U.S. native speaker's perspective.)

"Until when ..." is okay-ish, if a bit stilted. But "Until when do I have time ..." is just too clunky to be considered good colloquial English. See J.R.'s response for good ways to use "until when".

But this answer is to highlight what a previous comment pointed out: that the most natural way to say this would use the word "due":

When is the/this/our project due?

This is exactly how my students would ask me, multiple times throughout the semester.


Until when do I have time to finish this project?

I think there are two problems here:

So we could say

By when do I have to finish this project?

...and if we aren't squeamish about finishing a sentence with a preposition, a UK speaker speaking informally might be likely to say:

When do I have to finish this project by?

To answer your title question though, "Until when" is perfectly natural for other cases:

"I'm working in the library."
"Until when?"
" 'Til lunchtime. I have to hand in this project by this afternoon"

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