Which one of the following is correct?

Enter the number which you need the square root of.


Enter the number of which you need the square root.

  • Enter, not 'entre', and 'the square root'. Mar 15, 2022 at 9:12
  • 1
    The traditional rule is that 'it's wrong to end a sentence with a preposition', but this isn't applied strictly nowadays. However, in this case I think your second version is more appropriate (with the corrections suggested by Michael). See this Mar 15, 2022 at 9:17
  • 1
    I think most native speakers wouldn't bother with which (or equivalent / interchangeable that) in such contexts. Just Enter the number you need the square root of. Mar 15, 2022 at 12:34
  • Enter the number for which....
    – EllieK
    Mar 15, 2022 at 12:37

3 Answers 3


In general, yes you can end a sentence with a preposition, however some teachers/grammarians don't approve of it. Nevertheless, many native English speakers use prepositions at the end of sentences. It's a controversial subject for some.

Anyway, your examples are a bit awkward, and not very natural, although they would be understood. I would say if it's possible, then rewording is the way to deal with dangling prepositions.

Try this instead

Enter a number to calculate the square root that you need.

  • I would take a guess that a downvote could be because the answer was a 'This is what I think' one, and didn't include any link to reference material. Mar 15, 2022 at 11:55
  • 1
    Downvoters are not obliged to provide any reason for their actions, and absence of this does not necessarily merit the label of 'drive-by', which has implications of random senselessness. Voting on here is as much to regulate the site as it is to award points to individuals. Mar 15, 2022 at 12:39
  • I think the downvote is for misunderstanding how the question marks are used. The OP is asking which is correct by putting question marks at the end of each. They are not presenting the statements as questions.
    – EllieK
    Mar 15, 2022 at 12:39
  • 2
    @EllieK the title of the question makes it clear that the OP thinks that these sentences are questions.
    – JavaLatte
    Mar 15, 2022 at 13:42

It is not universally agreed by grammarians that there should be a 'rule' about not ending a sentence with a proposition. Even if there is, it is often ignored or relaxed in modern times for informal communications. In emails, text messages, and notes to friends, it's perfectly fine. But if you're writing a research paper or submitting a business proposal and you want to sound very formal, or to avoid upsetting people (or teachers) who support the alleged 'rule', avoid ending sentences with prepositions.

It would appear that some people are determined to hold on to this rule, no matter how many times they are informed that it really isn’t one.

Ending a sentence with a preposition (Merriam-Webster)

It is often alleged that Winston Churchill said, of the so-called 'rule', something like 'This is the sort of nonsense up with which I will not put', but it has been shown that he almost certainly didn't say it.

Note: enter, not 'entre', and 'the square root'.


Both (preposition used before 'which' and preposition used at the end of the sentence) are correct.

In a formal style we place the preposition before 'which'.

[ 'centre'(UK) and 'center'(US) are both correct. But 'entre' is not correct. It is 'enter'.

'the square root']

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