Opinion: serial commas

CommaI have a confession to make: I haven’t put together a style guide for posts I make on this blog. The consistency of style leaves a lot to be desired. It’s time to take my own advice and develop a style sheet.

And I would be very interested to receive your opinions on what you would like to see. Do you prefer a certain style? Do you find some style choices distract you or make the content harder to understand?

I’m going to start with punctuation and perhaps one of the most controversial of style differences – the serial comma. The serial comma is also referred to as the Oxford comma or the Harvard comma.

The serial comma is the comma that follows the penultimate item in a list of three or more things and comes before the and or or:

I like cake, biscuits, and ice cream.

I don’t think it is necessary there. It isn’t serving a meaningful purpose (in my opinion). The sentence could be punctuated as below and make perfect sense:

I like cake, biscuits and ice cream.

However, I would use a serial comma here:

The restaurant serves chocolate cake, cookies and ice cream, and mango sorbet.

My preference is to only use serial commas when they help to avoid ambiguity. But what do you think? Please vote in the poll below and/or leave a comment. Thank you!


Capitalisation: family relationships

Writers are frequently confused about when to capitalise words such as mum and dad. It isn’t as complicated as it may seem. The general principles are as follows:

FamilyIf you are using the word in place of their name, you should capitalise:

I'm cooking dinner for Mom
She asked Dad to mow the lawn
"Oh no," said Grandma

This applies if you are using the word as a title as part of their name:

We went to visit Uncle Gareth
"I've got things to do," said Grandpa Joe

If you are using the word as a label – a description of relationship or kinship – you should not capitalise:

I'm cooking dinner for my mom
Jenny's grandmother plays tennis
He looks just like his brother

You can usually tell if you need a capital letter by substituting a proper name and deciding if it sounds strange:

I told Mother the cat ran away 
I told Helen the cat ran away
I told my Mother the cat ran away
I told my Helen the cat ran away
I told my mother the cat ran away

This isn’t foolproof because people do say ‘my Helen’ or ‘our Helen’ to distinguish between multiple Helens or to imply relation. However, the use of a possessive pronoun (my, your, his, her, our or their) is often a good indicator that you should not capitalise.

This is my second post on capitalisation (the first one was on capitalising months and seasons), and it is an expanded answer to Erik Porter’s question about whether to capitalise mom in the phrase my mom. I hope it helps!

Capitalisation: months and seasons

I know some writers find it hard to use capital letters correctly; New Hart’s Rules has an introduction to capitalisation you might find reassuring:

Capital letters in English are used to punctuate sentences, to distinguish proper nouns from other words, for emphasis, and in headings and work titles. It is impossible to lay down absolute rules for all aspects of capitalisation … the capitalisation of a particular word will depend on its role in the sentence, and also to some extent on a writer’s personal taste or on the house style being followed.

The most important thing, I think, is to consider why you have used a capital letter – nouns don’t automatically need one.

There are some general principles you can use to guide you. The convention for months and seasons is fairly simple. I have included days and festivals below because they are often queried at the same time.


The names of days are capitalised:

She was born on a Wednesday
Can I visit next Saturday?


The names of months are capitalised:

The referendum will be held on 23 June 2016
I'm going on holiday in April


The names of seasonSprings are not capitalised:

I like to visit the beach in summer
There was a distinct lack of snow this winter

However, you should use a capital letter if you have personified the season:

And Winter shook his frosty mane
The warm sun ended Spring's slumber

Festivals and holidays:

The names of festivals, holy days and holidays are capitalised:

We are preparing for Ramadan
I don't like Halloween
What are you doing on May Day?

If you would like more information on using capitals, I recommend starting with Trask’s Guide to Punctuation. If you would like additional guidance, New Hart’s Rules is a useful style guide for UK publishing and is fairly thorough on the topic on capitalisation.


New Hart’s rules: the handbook of style for writers and editors (2014) 2nd edn. Oxford: Oxford University Press.

Trask, R. L. (1997) The Penguin guide to punctuation. London: Penguin Books.

Possessive apostrophes

Trask writes that possessive apostrophes are the most troublesome of apostrophes, and apostrophes are the most troublesome of punctuation marks. (I think commas must give apostrophes a run for their money.)

The basic rule for possessive forms is that ’s is added to the end:

Henry's book

If the noun ends with s, the same rule usually applies:

Charles's shoe

The first exception is for a plural noun that already ends in s:

my parents' holiday
the ladies' bathroom

These words are not pronounced with an extra iz sound, and so we don’t indicate an extra s in writing.

This brings us to the second exception. If the possessive form of a noun ending in s is not pronounced with an extra s, it only takes an apostrophe:

Aristophanes' plays
Bridges' marmalade

The final exception is for pronouns:

Whose is this? 
The essay is hers

But this does not apply to possessive indefinite or impersonal pronouns:

one's conscience
someone's lunch

I have previously covered its as a possessive form, and it is perhaps the pronoun most commonly incorrectly assigned an apostrophe.

Fowler’s Dictionary of Modern English Usage gives a comprehensive breakdown of exceptions and usage in more complicated situations, and I highly recommend it if you are worried about using apostrophes correctly.


I have previously covered how to use an en dash (–) and an em dash (—). Now to turn to the thing they are not: a hyphen.

A hyphen (-) shows that the matter it is attached to is not a complete word by itself. It should not be used with a space at both ends, although sometimes it is appropriate for it to have a space at one end.

The use of hyphens is often a matter of style. But they are used to do the following things:

  • join compound words
  • join compound modifiers
  • attach prefixes
  • indicate a piece of a word
  • indicate a word break at the end of a line

You might have heard of soft hyphens and hard hyphens. Soft hyphens are those that indicate word division at the end of a line. Hard hyphens are those that indicate words or parts of words are joined together to form compounds. There’s no difference in size or shape.

Hyphens are also used to indicate stammering or paused speech:

'W-w-what are we to do?'

And they indicate the omission of the second part of a hyphenated expression or solid compound:

three- and five-door cars
over- and underpaid employees

If you would like to find out more about when to use a hyphen, I can recommend the Penguin Guide to Punctuation for a thorough and simple explanation.

Em rules

Last week I posted about en rules. An em rule (—) is twice the length of an en rule (–). They are also referred to as en dashes and em dashes.Book

You will often see em rules used closed up (no spaces on either side) as a parenthetical dash; this is usually the preferred style for US publishers (instead of spaced en rules).

A spaced em rule can indicate the omission of a word; a closed-up em rule can indicate the omission of part of a word. It can also be used closed up in written dialogue to indicate a sudden break or interruption:

'You probably shouldn't put your knife in the toast—'

It is unusual but you might see some writers use a single closed-up em rule to set off dialogue instead of using quotation marks:

—Will he make it for dinner tonight?
—Not in this weather!

You may also see a closed-up em rule between an introductory noun (or nouns) and the pronoun introducing the main clause:

Cars, thunder, the neighbour's cat—nothing disturbed the plucky dog.

Em rules are used in indexes to indicate a repeated word, and they are sometimes used to indicate a repeated author’s name in consecutive bibliographic entries.

En rules

KeyboardYou are probably familiar with two types of dashes: the en rule and the em rule. Neither is to be used as if it is a hyphen.

The en rule (–) is longer than a hyphen (-) and half the length of an em rule (—).

You will often see it used with a space either side as a parenthetical dash; this is usually the preferred style for British publishers (the alternative is a closed-up em rule).

When considering the other uses, it might be helpful to think of the en rule as meaning (roughly) and or to.

The en rule should be used closed up (with no spaces either side) in elements (usually figures) that form a range:

pp. 18–25        1865–72        Monday–Friday

The en rule should also be used at the end of unfinished number ranges.

It is important to remember to always write from xxxx to xxxx or xxxx–xxxx. Do not use a combination of the two. The same applies when writing between xxxx and xxxx.

An en rule can be used closed up to express connection or relation between words, to express an alternative (in a similar way to a solidus) or to indicate joint creators (a hyphen between the names would suggest it was only one person).

En rules can also be used to indicate individual missing letters:

'The utter b – – – – – – !' she shouted.

It isn’t common to see this any more; people tend to be able to cope with seeing rude words spelt out.