Punctuation in English Grammar
Main punctuation marks
| Mark | Symbol | Main function | Example |
| Full stop / period | . | Ends a statement | The lesson finished at four. |
| Comma | , | Separates elements within a sentence | After class, we went to the beach. |
| Semicolon | ; | Links two closely related sentences | It rained all week; nobody minded. |
| Colon | : | Introduces a list, explanation or quote | There is one rule: speak English. |
| Apostrophe | ' | Shows possession or omission | the teacher's desk, don't |
| Quotation marks | Enclose direct speech or quoted text | She said, "We start at nine." | |
| Question mark | ? | Ends a direct question | Where are you from? |
| Exclamation mark | ! | Signals emphasis or strong feeling | What a view! |
| Hyphen | - | Joins words or word parts | well-known, twenty-three |
| Dash | – | Marks a break or an aside | He passed, just barely. |
| Parentheses | ( ) | Enclose extra information | The course (four weeks) starts in July. |
| Ellipsis | … | Shows omitted words or a trailing thought | She hesitated… |
The comma: five jobs
The comma is the most used and most misused mark in English. Almost every comma question comes down to one of these five functions.
| Job | Rule | Example |
| Listing | Separates three or more items | We visited London, Oxford and Brighton. |
| Joining | Before and, but, so, or linking two full sentences | She studied hard, and her English improved. |
| Introducing | After an opening word, phrase or clause | After the exam, everyone relaxed. |
| Bracketing | Around non-essential information | My teacher, who is Irish, speaks fast. |
| Addressing | Around a name or direct address | Thanks, Anna, for the notes. |
Semicolon vs colon
| Semicolon (;) | Colon (:) | |
| Purpose | Connects two balanced, related ideas | Announces what follows |
| Before the mark | A complete sentence | A complete sentence |
| After the mark | A complete sentence | A sentence, list, phrase or quote |
| Also used for | Long list items containing commas | Titles and subtitles, ratios, times |
| Example | The exam was hard; the results were good. | The results were clear: everyone passed. |
The apostrophe: only two functions
| Function | Form | Example |
| Contraction | Replaces missing letters | don't, it's (= it is), we're |
| Singular possessive | Noun + 's | the student's book |
| Plural possessive | Plural ending in -s + ' | the students' books |
| Irregular plural | Noun + 's | the children's teacher |
| Never | Plain plurals, or its as possessive | apples (not apple's), its own |
British vs American conventions
| Feature | British English | American English |
| Quotation marks | Usually single: 'hello' | Usually double: "hello" |
| Comma/full stop with quotes | Outside, unless part of the quote | Inside, as a rule |
| Abbreviations | Mr, Dr, St (no stop) | Mr., Dr., St. |
| Serial (Oxford) comma | Often omitted | Commonly used |
| Time | 9.30 a.m. | 9:30 a.m. |
| Dates | 21 August 2026 | August 21, 2026 |
Hyphen, dash and brackets
| Mark | Length | Use | Example |
| Hyphen (-) | Shortest | Joins words and numbers | a well-known author, twenty-three |
| En dash (–) | Medium | Ranges and connections | pages 10–15, the London–Paris route |
| Em dash (—) | Longest | A break, aside or afterthought | He passed — just barely. |
| Parentheses ( ) | Not applicable | Skippable extra detail | The course (four weeks) starts in July. |
Common mistakes at a glance
| Mistake | Incorrect | Correct |
| Comma splice | It was raining, we stayed inside. | It was raining, so we stayed inside. |
| Its vs it's | The city has it's own dialect. | The city has its own dialect. |
| Plural apostrophe | fresh apple's | fresh apples |
| Missing comma in an aside | My teacher who is Irish speaks fast. | My teacher, who is Irish, speaks fast. |
| Question mark after indirect question | He asked where I lived? | He asked where I lived. |
| Multiple exclamation marks | Amazing!!! | Amazing! |
| Hyphen used as a dash | He passed - just barely. | He passed — just barely. |
