Skip to content
Free public beta until December 4, 2026: every course is open, no card needed. After that, the first chapter of each course stays free and full access is a one-time $39 ($19 for up to 100 founding members chosen for helpful feedback). Your progress is kept. How the beta works

Every punctuation mark and its job

Each mark answers one question about the words around it. Ask the question and the mark picks itself.

Start from the words, not the mark. Ending a sentence? A period for a statement, a question mark for a question, an exclamation point for strong feeling. Joining, separating, or setting off with a comma? That decision has its own cluster, Every comma decision. Two complete sentences, closely related, with no joining word? Semicolon. List items that already contain commas? Semicolons between the items. A complete sentence announcing what comes next: a list, an explanation, an example? Colon. A break or aside you want loud? Em dash. An aside you want quiet? Parentheses; your own note inside someone else's quotation goes in square brackets. Two words working as one describer before a noun? Hyphen. Ownership, or letters left out? Apostrophe. Someone's exact words, or the title of a short work? Quotation marks. Words cut from a quotation? Ellipsis. Line breaks in quoted poetry, or and/or? Slash.

Ending a sentence

Term

period

See section →
The mark ( . ) that ends a statement.

Example

The mail arrived early. / Is it open? / We won!

Is it a statement? Period. A question takes a question mark; strong feeling takes an exclamation point.

The comma

The comma's four jobs and the places it never goes; start there for any comma question.

Joining and announcing

See section →
A semicolon used alone to join two closely related independent clauses.

Example

I packed a bag; the trip starts tomorrow.

Are both sides complete sentences, closely tied in meaning, with no joining word? Semicolon.

See section →
Semicolons used to separate list items that already contain commas.

Example

We stopped in Austin, Texas; Tulsa, Oklahoma; and Denver, Colorado.

Does any item in the list already contain a comma? Then semicolons separate the items.

Term

colon

See section →
A punctuation mark that announces something following it, such as a list or explanation.

Example

Bring three things: a pen, paper, and a laptop.

Is what comes before it a complete sentence that announces a list, explanation, or example? Colon.

Setting words apart

Term

em dash

See section →
A long dash (—) used to set off a dramatic interruption or emphasized addition.

Example

The answer — the one nobody expected — was simple.

Want the break or the aside to be loud? One dash, or a pair around the aside.

See section →
Punctuation marks enclosing a supplemental aside that could be dropped without harming the sentence.

Example

The meeting (the third this week) ran long.

Want the aside quiet, so the sentence stands complete without it? Parentheses.

Inside and between words

Term

hyphen

See section →
A short mark (-) joining words into a single compound modifier before a noun.

Example

a well-written essay / the essay is well written

Are two words working as one describer before a noun? Hyphen them; after the noun, usually drop it.

Term

apostrophe

See section →
A punctuation mark showing possession or marking a letter dropped in a contraction.

Example

the dog's bone / it's raining / its collar

Does it show ownership, or mark letters left out? Apostrophe; possessive pronouns like its and theirs never take one.

Quoting

See section →
Punctuation marks enclosing someone's exact spoken or written words, or certain titles.

Example

"I'll be there," she said.

Someone's exact words, or the title of a short work like a song or article? Quotation marks; long works go in italics.

Term

ellipsis

See section →
Three dots marking words left out of a quotation, or speech trailing off.

Did you cut words from a quotation? Three dots mark the gap, and the shortened quote must keep its meaning.

Term

slash

See section →
The slanted line (/), used in essays mainly to mark line breaks in quoted poetry.

Example

3/4 / the park, the pool, or both rather than and/or

Line breaks in quoted poetry, a fraction, or and/or; formal prose usually spells and/or out in words.