Hyphens with Prefixes and Suffixes

Em Rule, En Rule, and HyphenUse a hyphen where a prefix is added to a word that begins with a capital letter or a number, and to avoid a clash of consonants or vowels. We have pre-invasion politics of post-1945 warfare; and the school of neo-Impressionism.

[Note: In US-English an en rule is used to attach a prefix: post–1945 warfare.]

Hyphens are also used to avoid confusion between two words. We have: the chair was recovered from an old barn and re-covered with fabric.

The word ‘ex’ is usually followed by a hyphen: ex-worker, ex-wife, etc. When ex precedes a compound with two or more capitalised words it becomes difficult to punctuate meaningfully. Is ‘ex-Labour Minister Gordon Brown’ someone who was once a minister of labour, or a current minister who once belonged to a party called Labour, or even someone who was once a Labour minister? Using a second hyphen is not recommended and we are left with the option of replacing ‘ex-‘ with ‘former’ or rephrasing. For direct speech, which should not be changed, you might have the option of converting to reported speech.

Where a word, such as ‘style’ or ‘ready’, is behaving as a suffix it is also necessary to use a hyphen: to play music in the style known as dub you have to use ‘dub-style techniques’; the banks reacted to the consequences of their own greed by becoming unhelpfully risk-averse; HD-ready TVs were on sale long before broadcasts in HD were available.

Suffixes tend to be hyphen-less, and are usually open or closed. Where ‘less’ or ‘like’ are added to a word that has two ls of its own a hyphen is used. For example, we have ball-less games. Also use a hyphen when creating or inventing a combination with ‘-less’ or ‘-like’, or with an unusual combination. I wrote ‘hyphen-less’ above to demonstrate this point, and we have lifeless (a common word, so a closed compound) terrain on Mars-like planets.

Other suffixes are usually closed: waterproof, moonscape, moneywise, nationwide, etc.

Hyphens when Reproducing Foreign Languages

It’s not good to add hyphens willy nilly. If a word or phrase is so foreign that it is in italics then it would be unwise to add any punctuation unless you were correcting a known, verified, and accepted error. It is ‘ex post facto’ (or ‘ex post facto’, depending on the publication); writing ‘ex-postfacto’ could confuse the reader. Notice the hyphen (and lack of) in: ‘The actor Cung Le is a san shou practitioner. San shou is a martial art therefore he is a martial-art practitioner.’

Hyphens and Numbers

Use a hyphen when spelling numbers over 20 that are not divisible by ten. We have ‘twenty-one’ and the ‘twenty-first’, and ‘one hundred and thirty-two’; but note that it is ‘his one-hundred-and-fifth birthday party’ (as ‘one-hundred-and-fifth’ is one adjective, describing the birthday party, it’s linked by hyphens).

Fractions traditionally take a hyphen. We should have one-half of a pie (or better three-quarters). Current British use tends to prefer an open compound: we should have one half of a pie (or better three quarters).

As I have a finger in this pie I’ll add that I prefer to use the hyphen in fractions involving only numbers (so ‘a half of the pie’ is not hyphenated but ‘one-half of the pie’ is). A half-pie can be good, although it suggests a pie that is complete but only half the size of a full-size pie. She ate one-quarter of my pie [number]; she ate a quarter of my pie [proportion].

Don’t use a hyphen between an integer and a fraction except where the whole sum is part of a compound. We can have ‘one and two-thirds of a pie’ (almost two pies—must stop thinking about pies), and ‘the MGB can be classed as a two-and-a-half-seater sports car—the half-seat is little more than a ledge.’

Hyphens and Compass Points

Compass points and hyphens are difficult to encompass—I hope the following will be clear without causing you to keel over. The best I can do is: compass points involving two or more terms are usually hyphenated.

Here’s a list from north to east.

  • North
  • North by east
  • North-north-east
  • North-east by north
  • North-east
  • North-east by east
  • East-north-east
  • East by north
  • East

The grammar behind the compass wheel’s 360° can be divided into four segments of 90°. We’ll look at north to east; you should be able to work the rest out from there. Halfway between north and east we have the north-east (hyphen), which is 45° east of north. At the midpoint of north and north-east we have north-north-east, which is 22.5° east of north (and so, between north-east and east we have east-north-east). In the middle of north and north-north-east we have north by east (no hyphens), which is 11.25° east of north [Note: some prefer hyphens for the ‘by’ points, such as north-by-east]. And finally, halfway between north and north by east, we have north-half-east. The Americans do things a little differently, preferring the closed compound, e.g. northeast, and hyphens for the ‘by’ points, e.g. north-by-east.

Winds (as nouns) are closed compounds (no hyphens): a southeaster is a wind blowing from the south-east. The direction of wind is particularly difficult to pin down. We have a northerly wind (blowing from the north) and a northward or northern wind (blowing from the south). It seems logical that a wind blowing from the north-east would be a north-easterly (hyphen) wind. The COED gives the hyphenated spelling but New Hart’s Rules (both by Oxford University Press—experts in this field) gives the closed form: northeasterly (as the Americans and Collins would spell it). I’m guessing this is a typo. However, New Hart’s Rules also gives the hyphenated ‘south-by-east’, whereas the COED gives the unhyphenated ‘south by east’. And the confusion doesn’t end there. Collins English Dictionary gives an entry for ‘northbound’ (northward), yet the COED seems to want an open compound, north bound, which would no doubt be hyphenated as an adjective: north-bound train. [I did mention at the start that hyphens were difficult. This mixed usage by the same (expert) publisher is indicative of how difficult.]


Capitalised compounds are not hyphenated, as mentioned earlier, so we have North East England and South East Asia.

How to Produce Hyphens

On a UK qwerty keyboard the hyphen key is between the ‘0’ and the ‘=’ key. It also functions as the minus sign.

I hope that’s clear. Sometimes, when it comes to hyphens, it’s necessary to consult your choice of dictionary. Remember that dictionaries contain differences and be careful not to mix spelling styles in the same written work.

[As with all these grammar posts, your interesting and insightful comments are invited.]