Put simply, a punctuation mark (or punctuation point in American English) is a mark used in writing to organise sentences and clarify meaning.

It’s easy to assume that they have been around as long as the letters they corral, but that is not the case. Glance at a vellum manuscript from the Middle Ages and you can see how the words run together in great spools, divided up by enormous illustrations of the capital letter at the beginning of each paragraph. Punctuation seems weirdly absent, and the idea of trying to read the text gives us a headache.

The forms and the functions of punctuation marks have evolved over time, often changing the most when adopted by new literary forms or technologies – like the novel or movable type.

You might encounter writers or grammarians (or both) who will insist that a misplaced comma could mean the difference between life and death, but common sense will usually be enough to iron out any ambiguities in a text. What a good grasp of punctuation will give you, however, is the appearance of a well-informed and organised mind, and who doesn’t want that?

Some punctuation marks are used slightly differently on either side of the Atlantic Ocean; some other languages use punctuation very differently or employ very different symbols. However, here are some of the basics of punctuation.

Classifications of punctuation marks

Let’s challenge syntactic conventions and start with the full stop (.), the most final of the terminal points: the mark that shows a sentence is over or that a word is an abbreviation (e.g., etc.).

Alternatively, if you’re looking for a bit more excitement, the exclamation mark (!) has been invigorating the end of expressions since Roman times. It appears on road signs to warn of potential hazards ahead and on social media comments to warn of bad writing. Surprisingly, it wasn’t even featured on typewriter keyboards until the 1970s.

If you like a little mystery, then the question mark (?) is for you. Even its origins are a little mysterious – some pointing the finger at Brother Alcuin of York in the Scriptorium with the Quill, others maintaining it’s an abbreviated version of the Latin quaestio. It indicates that the sentence or phrase preceding it is a question, but it isn’t used if the question is reported – for example, She asked me where I lived.

Pause points help direct and sort ideas on their way to the end of the sentence, and the hardest-working, most misunderstood one of them all is the comma (,). Commas are so busy because there are so many unglamorous jobs in a sentence and so many of them are left for commas to pick up – like parents and their offspring’s discarded clothing. If you want to list some items, separate them with commas; if you want to add some extra information to a sentence, sneak it in under the protective custody of commas. If there’s another clause that needs adding, a comma will ease its addition – for example, Yes, we can or That’s right, isn’t it?

Then there are the comma’s more sophisticated siblings, the colon (:) and the semi-colon (;). The colon will announce a list or some more detail to illustrate or amplify what was written before it. It should only follow a full sentence, so My favourite colour pencils are: red and scarlet is not correct, for example. It can also be found hanging about in between the hours and minutes when Americans write the time (like at 10:46 just now).

Semi-colons are best employed by bringing together independent clauses without getting any conjunctions involved.

For example,

My milkshake brings all the boys to the yard, but my yoghurt shuffle does nothing for them.

could be written as

My milkshake brings all the boys to the yard; my yoghurt shuffle does nothing for them.

They can also be used for lists if the phrases listed already contain commas, to keep things clear and organised, which after all is what punctuation is intended to do.

The apostrophe (‘) draws the ire of the grammar Nazi with as much regularity as the comma does. Over the centuries, its job description has changed slightly and its positions have been changed, but its twin role is quite straightforward: show a letter or two has been omitted (two o’clock) or indicate possession (Caesar’s Palace).

Hyphens (-) and dashes (—) are often confused with each other, as are parentheses (()) and brackets ([]). People often refer to a horizontal line in a text as a hyphen, but that name only applies to the shortest line that connects compound words (or should that be compound-words?); it’s the dash that does all the heavy lifting, standing in for commas or colons or parentheses when a little more drama is called for – you see?

Those same people (or at least people that might stand with the mistaken-hyphen people somewhere on a grammar Venn diagram) also say bracket when they mean a parenthesis (or round bracket, if we’re feeling indulgent). Parentheses seal off information that the writer wants to keep apart from the surrounding text for whatever rhetorical or practical reason (again, to keep things clear), whereas the brackets (or square brackets) are used in a more editorial way to indicate mistakes or clarifications.

Quotation marks (“”) or inverted commas (‘’) are used to indicate direct speech within a text – or to put something at an ironic distance (e.g. And here’s where the ‘magic’ happens). They were originally used in the margins to highlight important sections of Biblical text, but gradually moved among the words themselves.

“Did he say ‘direct speech’ just then?”

‘I believe he did. “Direct speech.”’

Americans like to use double marks, Britons opt for the single, though this is not uniformly observed now, and you are best to check with individual style guides if you ever need to write something formal. If there are quotes within quotes, both Americans and Brits will use the other version – again, to keep things organised.

The slash (/) (or more formally, the virgule, from virgula – Latin for twig) has been thrown some limelight since the advent of the Internet, and is used as a shorthand for or (as in Y/N for Yes or No or he/she). It also survives in its old role marking the end of a phrase or line when poetry or lyrics are quoted in a linear fashion (With the lights out/It’s less dangerous/Here we are now/Entertain us). It is more traditionally known as the stroke, particularly in Britain – famously reflected in the nickname for Derry (Londonderry) in Northern Ireland, Stroke City, which underlines the fact punctuation can sometimes ease political tensions.

Other punctuation marks include the ellipsis (…), which is not just three full stops in a row, but signifies a fading out, often used when writing dialogue, or a gap, often used in academic citations. There is also the pound sign or hashtag (#), which has taken on great importance in our marketing-inflected culture of hypertext and invisible communities.

Finally, there a whole barrow-load of punctuation obscurities and innovations, some addressing more pressing needs than others, such as the Interrobang (‽), the percontation point (⸮), the pilcrow (¶), the hedera (❧), and the asterism (⁂), all of which are worth a chase down the Google hole.

But hang on, there is another group of signals that we use to punctuate texts that we write and send every day: the emoticons. How long will it be before grammarians start defining exactly smiley faces and see-no-evil monkeys should be used in a formal academic article? Maybe it is already happening… J!!!