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I want to write a remark in parenthesis between an indefinite article and the rest of the subject. If I didn't write this clarification then using the "a" article would be correct; however for the clarification alone "an" should be used.

Which one of the following examples is correct? Both sound weird to my ears.

This experiment used an (arguably small) set of data.

This experiment used a (arguably small) set of data.

marked as duplicate by Edwin Ashworth, tchrist Jan 21 '18 at 19:18

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Try reading both versions out aloud. You'll hear that 'an' sounds much better.


To be true, ' arguably small ' is not parenthetical. It's a determiner of ' set of data ', and for that matter, an adjective phrase. Articles precede such determiners so use of 'an ' would be correct.

  • 1
    'Arguably small' is certainly being used as a parenthetical (additional information added as an aside) here. In << This experiment used an arguably small set of data. >> it's not. Contrast << The experiment did use a set of data. OK, arguably, it was small. >> with << The set of data the experiment used might be considered small. >> – Edwin Ashworth Jan 21 '18 at 19:50
  • To view 'arguably small' as parenthesis ( interpolation) would demand use of an 'a' as it's an en extra. – Barid Baran Acharya Jan 22 '18 at 3:36
  • 1
    No; the a/an choice is totally dependent on facilitation of reading, which trumps matters of grammar, shibboleths about the need for no changes to be necessary to the matrix sentence when a parenthetical is omitted.... This has been covered comprehensively before on ELU (and this trumps other rules hereabouts). – Edwin Ashworth Jan 22 '18 at 9:37

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