Endmarks: All sentences need an endmark: a period, question mark, exclamation point, or ellipsis. Never put two endmarks at the end of the same sentence.
Apostrophes: For singular ownership, generally add’s; for plural ownership, generally add s’.
Commas: In direct address, use commas to separate the name from the rest of the sentence. In lists, place commas between items in a list, but not before the first item. Before conjunctions, when combining two complete sentences with a conjunction, place a comma before the conjunction. If you have one subject and two verbs, don’t put a comma before the conjunction.
Hyphens: If two words create a single description, put a hyphen between them if the description comes before the word that it’s describing. Don’t hyphenate two-word descriptions if the first word ends in -ly.
Colon: Use a colon after an independent clause that precedes a list and to separate an explanation, rule, or example from a preceding independent clause.
Semicolon: Use a semicolon to join independent clauses in compound sentences that do not have coordinating conjunctions (and, or, but, nor, for, so, yet) and commas as connectors. Words like however, moreover, thus, and therefore, are often used as connectors in these sentences. You can also use semicolons to separate long or complicated items in a series that already includes commas, and to separate two long or complex independent clauses joined by a coordinating conjunction if confusion would result from using a comma.
