Are the following equally appropriate to be used at work with a colleague or client? I don't want to be informal, but I don't have to be too formal either.

Let me know when you are free so that we can discuss this in more details.


Let me know when you are available so that we can discuss this in more details.


Let me know when you are not busy so that we can discuss this in more details.

Disclaimer: I'm not a native English speaker (as if I had to explain that)

  • 7
    Just thought I'd point out that you want "more detail" (singular) rather than "more details". (This isn't what you're asking about of course.)
    – Noldorin
    Jan 18, 2011 at 18:00
  • 4
    Just to expand on @Noldorin's comment, I would also drop the word more, it's redundant. …so that we can discuss this in detail. It is also acceptable to drop the word "that," since so is used as a conjunction here. You would keep the word more only if you want to emphasize the fact that you've already had a substantial discussion.
    – ghoppe
    Jan 18, 2011 at 18:21

2 Answers 2


All three variations of the sentence you give are grammatically correct, and are virtually (but not completely) equivalent. There are a few points worth noting in particular.

  1. It is far more conventional to say "let me know when you are busy" than "let me know when you are not busy". The negative is considered redundant, and they are understood to mean the same thing, i.e. they are both enquiring about availability.

  2. Saying free or available rather than busy may be considered a more "positive" enquiry. It may also simply mean that you expect the person to be busy rather than free, rather than the other way round.

  3. Saying available rather than free is considered slightly more formal, though I wouldn't worry much about usage cases. (Most people wouldn't think twice if you used either in a formal or colloquial situation.)

  • 1
    ...grammatically correct modulo replacing "details" with "detail".
    – Marthaª
    Jan 18, 2011 at 18:56
  • 2
    +1 For the comprehensive answer, but I feel obliged to note I have often asked people to give me a call when they're "not busy."
    – Robusto
    Jan 18, 2011 at 19:15
  • @Robusto: Oh indeed, that makes the most sense there. My comment was specific to "let me know ...".
    – Noldorin
    Jan 18, 2011 at 19:20
  • @Martha: If you check my comment on the main post I've mentioned that. :)
    – Noldorin
    Jan 18, 2011 at 19:21
  • @Martha (re your edit): What was wrong with "enquiry"? In BrE we typically use "enquiry" in the general meaning of "question", while "inquiry" tends to be reserved for the sense of "formal investigation". Jan 18, 2011 at 19:29

All three of those are equally appropriate, and as far as I know, completely equivalent. The only thing I would change would be to say "in more detail" rather than "in more details".

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