Serial Comma, Title Case & -ise/-ize Across the Guides

Three small things trip people up again and again: the comma before and in a list, which words to capitalise in a title, and whether it is -ise or -ize. None is hard once you have seen the rule — this card sorts all three at a glance, with a link to the fuller article for each.

Two more quick pointers before the sections below. A comma is not the only way to separate a list — for lists that already contain commas, you can use semicolons to keep them clear: I visited Leeds, in the north; Bristol, in the west; and Dover, on the coast. And title case is only for titles — do not use it for an ordinary sentence, where just the first word and any names take a capital.

1. The serial (Oxford) comma

The serial comma is the comma right before and at the end of a list: boots, socks, and a water bottle.

• You do not have to use it — boots, socks and a water bottle is fine too. British schools often leave it out; it is more common in American writing.
• But it can stop confusion. Compare I invited my friends, Sam and Priya (are Sam and Priya my friends, or three separate groups?) with I invited my friends, Sam, and Priya — the extra comma makes it clearly three.
• The real rule is consistency: use it every time in a piece, or leave it out every time — do not switch. More in Commas & the Oxford Comma.

2. Title case

When you write the title of a book, film, song or essay, capitalise the important words and leave the little joining words lowercase:

• Capitalise: nouns, verbs, adjectives, adverbs — The Lord of the Rings, Stranger Things, How to Train Your Dragon.
• Lowercase: short joining words like the, a, an, of, and, to, in — unless one is the first word of the title.
• Always capitalise the first and last word, whatever they are.

The full version, and when to use plain sentence case instead, is in Title Case & Sentence Case.

3. -ise or -ize?

Words like organise / organize, realise / realize, recognise / recognize:

• British schools usually teach -ise — use that, and stay consistent.
• American English uses -ize.
• The twist: some British publishers (and the Oxford dictionaries) actually prefer -ize too, so a British book with organize is not wrong — just a different house style.

Pick one and keep it across the whole piece. More in Organise or Organize?.

The thread running through all three

Notice the same rule underneath each: choose a style and stay consistent. Oxford comma or not, title case chosen and kept, -ise or -ize held all the way through. A reader forgives the choice; what they notice is the switching.

And a small reassurance: none of these three will sink a piece of writing on its own. A missing Oxford comma, a title in sentence case, an -ize where you meant -ise — a reader understands you either way. What they notice is switching mid-piece, so the fix is always the same: choose, then hold it.

Where next

• Punctuation — the young-learner hub — the bigger map this sits inside
• Commas & the Oxford Comma — the serial-comma rule in full
• Title Case & Sentence Case — capitalising titles and headings
• Organise or Organize? — the -ise/-ize family