I'd like to know the role of parentheses on a phrase. For example, which of the following is right, "it has an (unique) index" or "it has a (unique) index".

  • 1
    You could side-step the issue: It has an index which is unique. Or just remove the parentheses: It has a unique index. What purpose do the parentheses serve? Nov 5, 2018 at 21:38
  • If parentheses force this kind of ambiguity, then remove them or rephrase the sentence. This is not the right kind of grammatical hill to plant your flag on. Nov 6, 2018 at 4:35

1 Answer 1


The paratheses indicate that it's an additional optional piece of information. But you still read it as if it's there, so the starting y sound of unique still dictates it should be a, not an:

It has a (unique) index.