The phrase “until when” may sound unnatural to many people, especially non-native speakers. This page explains the phrase’s meaning and provides examples to show in what circumstances it is correct or incorrect to use “until when.”
Is “Until When” Natural and Common?
The phrase “until when” is basically used to ask “how long” or “by when.” However, depending on the sentence structure, it is not always easy to use the phrase correctly. It is natural to say “until when”, but there are also more common alternatives to express the same.
The Google Ngram Viewer reveals that the term “until when” appears quite commonly in written English. The term can form part of a question, or it can also be a response to a question, as shown in the examples in the below section.
The Google Ngram Viewer for the UK shows that as the starting words of a sentence, its use has increased slightly in the last 70 years, whereas its use in the middle of a sentence used to be extremely common but has since reduced quite substantially.
The Google Ngram for the US shows that its frequency in the middle of a sentence has risen steadily for 70 years and is now more frequent than in American English than in British English.
The use of “Until when” at the start of a sentence has also risen steadily in the US and is used with the same frequency as in the UK.
What Does “Until When” Mean?
“Until when” can have several meanings in English, but it essentially means “by what time?” or “for how long?”
It is mainly used in two different ways. The first is as the start of a question, and the second is as a response to a question.
The following examples highlight the meaning a little more clearly:
1. As a question
- Until when are you accepting submissions for the football team?
- Until when are you planning on staying?
- Until when do we have to give you the project?
2. As the response to a question – (note that here, it is possible to use “until when”, which is the shortened version of the fuller phrase in brackets).
- Person A – I need you to stay late tonight after work
- Person B – Until when? (do you need me to stay)
- Person A – We are going to have to stay with my mother while the house is redecorated
- Person B – Until when? (do we have to stay with your mother)
Words to Use Instead of “Until When”
Some other words and phrases are synonyms of “until when”, which are more common ways of expressing the same thing.
Because of the varied uses of “until when”, there is not a “one size fits all” solution to replace it with a synonym, and it depends significantly on the context.
The main ideas that “until when” expresses is “how long”, “how much longer”, or “by when should something happen.” Therefore, the idea you express with “until when” determines which synonym is the most appropriate.
Here are some alternative ways to express the same idea:
- By when
- By what time
- For how long (how long)
- For how much longer
- When do I have to/need to
Here are some examples that show how the phrase “until when” can be replaced with synonyms in several different ways:
- Until when will you be at your friend’s house?
- For how long will you be at your friend’s house?
- When will you be leaving your friend’s house?
- Until when do you need me to keep making notes?
- For how much longer should I keep making notes?
- When should I stop making notes?
- Person A – I need you to wait for me after work
- Person B – (a) Until when? (do I need to wait for you)
- Person B – (b) How long do I need to wait for?
- Person B – (c) What time will you be ready to leave?
- Person A – I will be late, so you need to take care of your brother for a little longer
- Person B – (a) Until when? (do I need to take care of him)
- Person B – (b) For how much longer do I need to take care of him?
- Person B – (c) What time can I stop taking care of him?
Whilst the phrase “until when” may look a little unnatural to an English learner, it is perfectly acceptable when used in the correct context and structure. For example, it can mean “by what time” or “for how long” and can be used as the start to questions or as a response.