The em dash (—) is a versatile punctuation mark used in several situations in writing:
- To mark a break in a sentence or an abrupt change in thought, often adding emphasis or signaling a shift in tone.
- To set off additional information or parenthetical statements that are not essential to the main sentence, functioning similarly to commas or parentheses but with more emphasis.
- To replace commas, colons, semicolons, or parentheses for highlighting surprising or unexpected information.
- To set apart appositives that contain commas to avoid confusion.
- To introduce explanations, amplifications, or corrections related to the preceding material.
- To indicate interruptions in dialogue or sudden changes of thought in character speech.
- To bring focus to lists, especially when the list precedes the main clause of the sentence.
Importantly, em dashes are usually written without spaces on either side, though some style guides may vary. They tend to create a more informal tone than other punctuation marks and should be used sparingly, especially in formal or academic writing. They add a visual uniqueness that draws attention and breaks sentences into digestible parts. In summary, use the em dash when you want to emphasize parts of a sentence, indicate interruptions or sudden changes, set off clarifying or extra information, or replace other punctuation marks for stylistic effect.
