A sentence ends with one mark of punctuation that matches its purpose. Use a period at the end of a statement: I live near the station. Use a question mark when the sentence asks for information: Where do you work? Use an exclamation mark for strong feeling, surprise, or forceful commands: What a beautiful view! or Stop right there! These marks show the reader how the sentence should sound, and they are part of basic Sentence Structure.

Ending sentences with the right mark

Idea
Use a period at the end of a statement.
Use a question mark at the end of a question.
Use an exclamation mark at the end of strong feeling or urgency.

Start every sentence with a capital letter. The first word after a period, question mark, or exclamation mark always begins with a capital letter: She works on Monday. He studies at night. Use capitals for proper nouns too, such as names of people, places, days, months, and languages: Maria, London, Friday, April, English. Do not use a capital for a common noun unless it begins a sentence.

Capital letters for sentence starts and names

Idea
Use a capital letter at the start of every sentence.
Use a capital letter for names of people.
Use a capital letter for names of places and days.

Use commas to separate items in a list of three or more. Write each item on its own side of a comma: apples, oranges, and bananas. In British English, the final comma before and is often omitted, but it is still correct to use it. Commas also help the reader move through the list one item at a time: We packed shirts, towels, snacks, and chargers.

Using commas in simple lists

Idea
Use commas to separate items in a list.
Do not use a comma after the last item before and in a short list unless your style guide asks for one.
Use a comma when a sentence begins with a short opening phrase.

When two complete sentences are joined by a coordinating conjunction, put a comma before the conjunction: The train was late, and we missed the meeting. The comma comes after the first complete sentence and before and, but, or, so, yet, or for. Do not use a comma if the words on both sides are not complete sentences. The pattern is complete sentence + comma + coordinating conjunction + complete sentence. This pattern is part of clear Sentence Structure, and it supports natural writing in Making Statements and Asking Questions.

Commas before joining words

Idea
Use a comma before a coordinating conjunction when it joins two complete sentences.
Do not use a comma when the words on both sides are not complete sentences.
The coordinating conjunctions are for, and, nor, but, or, yet, and so.

A semicolon joins two complete sentences that are closely related and could stand alone. It sits between the clauses with no coordinating conjunction: The shop is closed; we will come back tomorrow. Use it when the second clause continues the same idea or gives a closely linked result. If the connection is loose, use two separate sentences instead. For many writers, a semicolon gives a smoother link than a full stop and is often useful in formal writing and Quotations and Reporting.

Connecting closely related clauses

Idea
Use a semicolon to join two closely related independent clauses.
Use a semicolon when the second clause shows a result or contrast.
Do not use a semicolon if the second part is not a complete sentence.

Use a colon after a complete sentence when what follows explains, names, or lists details. The colon comes after a general statement and before the specific information: We need three things: milk, bread, and eggs. It also introduces an explanation or example: He had one clear goal: finish the project today. Do not put a colon after a verb or preposition that still needs an object. The part before the colon must be complete on its own.

Introducing information with a colon

Idea
Use a colon after a complete sentence to introduce a list.
Use a colon after a complete sentence to introduce an explanation.
Use a colon before a direct example or quotation.

Use an apostrophe to show that something belongs to someone or something. With one owner, add 's: the teacher's book, the girl's bicycle, the company's office. With plural owners ending in s, add only an apostrophe after the s: the teachers' room, the dogs' owner. Apostrophes do not make regular plurals. Write three books, not three book's. For basic ownership patterns, the apostrophe is one of the most useful marks in English punctuation and appears often in Sentence Structure.

Showing ownership with apostrophes

Idea
Use an apostrophe and s to show one owner.
Use an apostrophe after plural nouns that already end in s to show shared ownership.
Do not use an apostrophe to make a regular plural.

A contraction combines two words into one shorter form, and the apostrophe shows where letters are missing. In don't, the apostrophe replaces the missing o from do not. In I'm, it replaces the missing letters from I am. In she's, it can stand for she is or she has, depending on the sentence. The apostrophe marks the missing part; it does not show possession in these forms. Common contractions are frequent in everyday speech and in Direct Speech.

Apostrophes in shortened forms

Idea
Use an apostrophe to show missing letters in a contraction.
A contraction keeps the meaning of the full words but uses fewer letters.
Common contractions include do not becoming don't and cannot becoming can't.

Use quotation marks around the exact words that someone says or writes. The quoted words go inside the marks: She said, "I am ready." If the reporting clause comes first, the quotation follows the comma: He whispered, "Be quiet." If the quoted sentence ends with a question mark or exclamation mark, that mark stays inside the quotation marks. Quotation marks also show exact words from a text, sign, or source, which is useful in Direct Speech and Quotations and Reporting.

double quotessingle quotes

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Use double quotes to show direct speech and exact words in most American style writingUse single quotes for direct speech in many British style texts, especially in print

Quotation mark styles in English

Region	Variant	Definition	Example
United States	double quotes	Use double quotes to show direct speech and exact words in most American style writing.	She said, I am ready now.
United Kingdom	single quotes	Use single quotes for direct speech in many British style texts, especially in print.	She said, I am ready now.

Scramble

Use parentheses to add extra information that is not essential to the sentence. The main sentence still makes sense without it: The meeting starts at 3 p.m. (please arrive early). Use dashes for extra information when you want a stronger pause or a sharper break: The final answer was clear and unexpected — nobody guessed it. The words inside parentheses or between dashes add detail, comment, or clarification, but they are not needed for the grammar of the sentence. Keep the main clause complete before you add the extra information.

Adding extra information clearly

Idea
Use parentheses for extra information that is not essential to the main sentence.
Use dashes to add a sudden extra idea or a strong break in thought.
Do not use extra punctuation when the added information is necessary to the sentence.

A complete sentence must have a subject and a verb and must express a full thought. If two complete sentences are written together without punctuation or a connector, the result is a run-on: I finished my work I went home. Separate them with a full stop, a semicolon, or a comma plus a coordinating conjunction. A fragment is different. It is missing a subject, a verb, or a full thought: Because I was late. Punctuation can separate sentences, but it cannot turn a fragment into a complete sentence.

Keeping sentences complete and clear

Idea
A run on sentence joins complete sentences without the right punctuation.
A fragment does not have a complete thought.
Punctuation can separate complete sentences, but it cannot turn a fragment into a full sentence.