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Are both Okay? I guess the problem is I could have made more than one error, but I could have made only one error

marked as duplicate by Jason Bassford, Peter Shor , Davo, Edwin Ashworth, Cascabel Jul 5 at 17:18

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    As you pointed out , it really comes down to error vs errors. In this context, without knowing whether its none, one or many, it makes more sense and sounds more natural to use the second sentence. – Balaz2ta Jul 5 at 6:31
  • @Balaz2ta I agree the second variant sounds more natural / less highfalutin, but the former is equally grammatical. "It's us!" doesn't make sense, but that doesn't stop everybody using it. – Edwin Ashworth Jul 5 at 16:15