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Island Man and Blessing
The comma is the most contested and most misused punctuation mark in English. Pupils inherit rules ("put a comma where you'd take a breath") that don't actually match how skilled writers use commas. Teaching commas well means going beyond folk rules to the actual conventions — and letting pupils see the choices skilled writers make.
About this video
Commas serve several distinct functions in written English: separating items in a list; setting off subordinate clauses from main clauses; enclosing parenthetical information; separating coordinate adjectives; before "and" or "but" joining independent clauses (the "coordinating conjunction comma"); and — most contested — the Oxford comma before the last item in a list. Each function has its own conventions, and skilled writers move between them fluently.
The teaching failure mode is presenting commas as a single rule ("where you'd pause") rather than a family of distinct functions. Pupils then apply the "pause" rule inconsistently, produce comma splices (joining two independent clauses with a comma instead of a full stop or semicolon), and never develop the discrimination that comes from understanding what each comma is doing.
The teaching that works tends to isolate each function, teach it with clear examples, practise it in pupils' own writing, and gradually build the repertoire. The Oxford comma is a great teaching moment for the fact that some punctuation is convention rather than rule — different style guides call it differently, and skilled writers make an informed choice.
The main comma functions worth teaching explicitly
- List commas. Separating items in a series ("bread, cheese, and wine"). Discuss the Oxford comma option.
- Subordinate clause commas. "Because it was raining, we stayed inside." The subordinate clause comes first, with a comma before the main clause.
- Parenthetical commas. "The book, which was old, sat on the shelf." Two commas enclose the extra information.
- Coordinate adjective commas. "A cold, wet morning" — but not "A bright yellow shirt" (adjectives serving different purposes).
- Independent clause commas. Before "and" or "but" joining two full sentences ("She smiled, but she did not answer.")
- Comma splice. Wrong: "She smiled, she did not answer." Two independent clauses need something stronger than a comma.
Discussion prompts
- What comma "rule" have you passed on to pupils that turns out to be a folk rule rather than a real convention?
- How do you teach the comma splice — one of the most common errors — without turning grammar into pure error-correction?
- Where in your teaching do pupils see published writers using commas in ways that break "the rules"? What does that show them?
Try this in your classroom
- Take a paragraph from a novel you're studying and remove all the commas. Give it to pupils to punctuate. Compare their versions with the original and discuss the choices.
- Teach the comma splice explicitly, with paired examples: "She smiled, she did not answer" (wrong) and "She smiled; she did not answer" (right). Discuss why.
- For one lesson, focus exclusively on parenthetical commas. Have pupils rewrite sentences to add parenthetical information, then take it away. Notice how meaning changes.