How do you reply to someone if you are confused about their question?
Eg: someone mailed me "How are you ensuring that the box is there?".
I am confused whether he meant Box A or Box B. How would I reply asking for clarifying the same? Which of the two expressions − "Are you asking about...?" and "Did you mean...?" − should be used?
Under the given context, there is no hard and fast rule stating which one should be used. Both equally applies in practice. It's just a matter of preference.
There is, however, a slight difference in the tenses of the constructs you've stated. "Are you asking about...?" is present continuous while "Did you mean...?" is past tense. A somewhat equivalent construct ought to be "Do you mean...?"
But that is all there is to it. You may even any of the following while keeping the semantics intact.
- Are you referring to...?
- Which one...?
I would explicitly quote his expression, and if you have the information available and it's not too onerous to explain, you can give him answers for both possibilities.
When you say "the box" to which box are you referring, Box A or Box B?
For Box B, I can see...
For Box A, there is a...
This clarifies that you found the question ambiguous but you are giving the most useful response you can by covering both cases.
Either "Are you asking about...?" or "Did you mean...?" is completely acceptable and sounds fine. The two phrases are equivalent.
You could ask for clarification like this:
When you say "the box", which box are you referring to: box A or box B?
