Usage and Grammar

Q. Help! Can you please tell me which is correct: “if one or more component is ineffective,” “if one or more components is ineffective,” or “if one or more components are ineffective.” The document I’m reviewing uses all three constructions, and I haven’t been able to find any solid guidance on which is correct.

A. Go with the last one. The adjective nearest the noun normally signals the number of the noun (e.g., “one or two components”; “one or more components”), so the plural components is the noun you want. And a plural subject requires a plural verb (are). Please see CMOS 17, section 5.138 (“Agreement in Person and Number”).