@dalehileman,
dalehileman wrote:Sorry Con but you misunderstand. A compound modifier is two or more words that constitute usually an adjective. Often in these cases the hyphen is absolutely essential
You're right. I realised after it was too late to edit my post. We are talking about ten-ton weights, five-mile hikes, six-hour waits, etc.
I had an idea that maybe British English was less strict than US English, but to my surprise I find that some say it is the other way around:
Grammar Monster says:
Quote: In the UK, your readers will expect you to use hyphens in compound adjectives.
In the US, your readers will be more lenient. The US ruling is: Use a hyphen if it eliminates ambiguity or helps your reader, else don't bother. If you're unsure, use hyphens. You won't be marked down for using hyphens.
The Hyphen Might Be Essential
Sometimes, a hyphen is essential to avoid ambiguity. Look at these examples:
a heavy-metal detector
a heavy metal detector
Both are correct, but they mean different things. The first device detects heavy metals. The second device detects metal, and the device is heavy. If we're talking about a device that detects heavy metals, then putting heavy metal detector would be wrong in the UK and the US.
My own experience is that UK writers often omit the hyphen from a compound modifier if there is felt to be no ambiguity.