Rules on hyphenating phrases

Question

I see a ton of questions on hyphenated words, specifically, but nothing on the more general question how/when they're supposed to be used vs omitted. Another great answer gives some general rules on hyphens:

A hyphen is used to join words in a compound construction, or separate syllables of a word, like during a line break, or (self-evidently) a hyphenated name.

..but this leaves the greater question of when this "compound construction" should be used, open.

Consider this a "canonical" usage question, then.

A common usage I see is "day-of-the-week" vs. "day of the week". Both of these seem correct, and are read out loud identically from what I can tell.

Some other common examples I've seen:

• "Video-of-the-month club"
• "Give-and-take arrangement"
• "State-of-the-art technology"
• "Friendly-looking person"

I see very little difference in meaning in the above phrases, both with and without the hyphens.

When should hyphens or dashes in multi-word (or is it multi word? or multiword?) phrases be used?

Answer 1

Compound constructions are oftend used/created when there is chance of ambiguity, in a way similar to how 'Let's eat grandpa' is put into its proper context by adding a comma between 'eat' and 'grandpa'.

For example, 'That is a friendly looking person' doesn't say much about how the person looks, only that he is friendly (for sake of the example assuming that 'looking person' is a thing).
'That is a friendly-looking person' says something about how the person looks, but it doesn't mean that person actually is friendly.

Use 'Can you get me the video-of-the-month', and everybody knows what you mean, at least conceptually speaking, but omit the hyphens, and the sentence just looks incomplete 'Can you get me the video of the month' (january, last august?).

'State of art technology' refers to the technology in (the making of) art, and the state that technology is in. 'State-of-the-art' means that something is the most modern, most advanced, etc, so a different meaning altogether.

Just like any other punctuation mark, hyphens have their uses, and the rules and guidelines you already found can help determine when they are best used in a text.

PS: Concerning 'multi-word'; some words are prefixed, while others are not. I can't promise that this site explains it all (if you haven't visted it already), but it does give some good background information on hyphenation.

Answer 2

Hyphens are used in compound adjectives to avoid confusion. You would use a hyphen where it is not possible to remove one of the words and still make sense (or make the same sense).

In your first three examples, removing any of the words would leave a nonsensical phrase:

"Video of the club"
"Give and arrangement"
"of the art technology"

In the 4th one "Friendly-looking person" you could remove 'looking' but you couldn't remove 'friendly'. The importance of 'looking' is that the person appears to be friendly (but may not be).

Here is a helpful site:

How do we know when to put a hyphen?

If you can use the word “and” between the two adjectives or words, then a hyphen isn't necessary.

She has a big blue book.

(Big and Blue are adjectives) Can we say: She has a big and blue book. (Yes, it is possible)

He is a world famous singer

Can we say: He is a world and famous singer. No, it doesn't sound correct so we need a hyphen to join the words world and famous.

Also, look at the following:

It's an old coal-mining town

Notice how we didn't put a hyphen between the word old and coal. If we had have done that, we would have been referring to old coal, as in coal that is old. We want to emphasis that the town in old and not the coal.

Here we can say it is old and a coal-mining one.