The Editor’s Manual
Free learning resource on English grammar, punctuation, usage, and style.
Use “a.m.” and “p.m.” to indicate exact time, and use numerals instead of words to denote the hour and the minute. These abbreviations are generally lowercased in running text, but they may also be capitalized.
When exact time is important, use numerals with “a.m.” or “p.m.” (“2:33 p.m.”); otherwise, use words (“two o’clock,” “two thirty,” “half past two”). In certain settings, the 24-hour system is used to show exact time (“14:33” or “1433 hours”).
Use the correct form of the verb with singular and plural subjects. To ensure subject-verb agreement, identify the subject and check whether it is singular or plural. Some subjects may appear plural but be singular.
“Any” can be singular or plural, depending on whether you mean “at least one” or “one or more.” It is generally used with uncountable and plural countable nouns in questions and negative statements, though it may be used with a singular countable noun for emphasis.
One of a group is singular (“one of them is” not “are”). But when “one of” is followed by “who” or “that,” check what is being described: one person or thing, or the plural set.
Use “either-or” to affirm the one or the other of two alternatives and “neither-nor” to negate them both simultaneously. Make sure that the elements joined using “or” and “nor” are grammatically balanced and parallel in structure.
“Either” is grammatically singular and used with singular verbs (like “is” and “has”) in formal usage. In informal usage, the word may be treated as either singular or plural.
“Neither,” which means “not either,” negates each of two possibilities individually. In formal writing, treat it as singular (“neither is”). In informal usage, it may take either a singular or a plural verb (“neither is/are”).
“None” may be either singular or plural, depending on whether you mean “not one” or “not any.” To refer to the individual members of a group, use a singular verb; for the entire group, use a plural verb.
Use “I” instead of “me” when it forms part of the subject (“You and I can work on this together”). When pronouns are joined using “or” or “nor” to form the subject, the verb should agree with the part closest to it (“Either you or I am right”).