Punctuation, Mechanics, and Style
Punctuation that changes meaning
Know the jobs of each mark. A comma separates introductory elements, items in a series, and nonessential information. A semicolon joins related independent clauses and separates complex series items. A colon introduces a list or explanation after a complete clause. An apostrophe shows possession or contraction; watch its (possessive) versus it's (it is), and their, there, and they're. A hyphen joins compound modifiers before a noun ("a well-known author") but not after ("the author is well known").
Restrictive versus nonrestrictive
Commas around a clause signal that it is extra information. "Employees, who work remotely, must log hours" implies all employees work remotely. "Employees who work remotely must log hours" restricts the rule to remote workers. This distinction is a frequent trap.
Mechanics and consistency
Capitalize proper nouns and the first word of sentences and salutations. Use numerals for dates and measurements, spell out numbers beginning a sentence, and keep formatting consistent within a document. Style questions reward consistency over personal preference.
Worked example
Sentence: "The manager requested three things a budget a timeline and a risk report."
Step 1: Add a colon after the complete clause: "requested three things:" Step 2: Separate list items with commas: "a budget, a timeline, and a risk report." Result: "The manager requested three things: a budget, a timeline, and a risk report."
Rule of thumb: a colon must follow a complete clause, and a nonessential clause must survive removal without changing the core meaning.