The Editor’s Manual
Free learning resource on English grammar, punctuation, usage, and style.
Abbreviated SI and other metric units do not have a separate plural form: don’t add “s” to form the plural of an abbreviated unit of measurement (10 km, not 10 kms).
“Indigenous Peoples’ Day” may be written with or without the apostrophe, depending on the style you follow.
The abbreviations “UK” and “UN” are generally written without periods except in certain styles. The abbreviation “EU” is always written without internal periods.
The abbreviation for United States may be written with or without internal periods: U.S. or US. Both styles are acceptable.
English has the “to”-infinitive (or full infinitive) and the bare infinitive. The “to”-infinitive can also appear as a split infinitive.
An infinitive (e.g., “to go”) is split when a word appears between “to” and the verb (“to not go”). It is fine to split the infinitive in English.
A gerund acts as a noun, while the present participle form of a verb helps form tenses, acts as an adjective, and appears in participle clauses.
A gerund is a verb form ending in “-ing” that functions as a noun. It can act as subject, object of a verb or a preposition, and subject or object complement. It exhibits both noun- and verb-like qualities.
You may either omit or include the comma after greetings like “Hi” and “Hello” in informal email salutations, depending on preference.
Use “Sincerely,” “Best wishes,” or “Regards” (or “Warm regards,” “Best regards,” “Kind regards”) to close a formal or business email. Don’t use casual sign-offs like “Cheers” or “Best” in formal communication.