English Language & Usage Stack Exchange is a question and answer site for linguists, etymologists, and serious English language enthusiasts. It only takes a minute to sign up.
Sign up to join this community
Why are year, pound and mile in the singular form in the phrases below?
Is that because they're acting as adjectives, which are always invariable in English?
Is it incorrect to say...
Those are called compound and hyphenated compound adjectives. And adjectives don't have plural forms.
Additional examples
three-storey building (
three-stories bulding)four-wheel drive (
four-wheels drive)32-bit processor (
32-bits processor)
Some adjectives can only be used to modify nouns, for example the adjective indoor. We can talk about:
But we don't usually say:
We call adjectives that appear before nouns attributive adjectives. The adjective indoor is called an attributive only adjective.
Other adjectives can't usually be used before a noun. We usually find these adjectives as the complements of verbs like BE, FEEL or BECOME. So we can say
But we cannot say:
Adjectives that we use like this are called predicative adjectives. The adjective afraid is a predicative only adjective.
We can use most adjectives as attributive adjective and predicative adjectives:
Sometimes we have two adjectives that look similar and mean the same thing. One of them is attributive only, and the other predicative only. For example, the adjectives live and alive. When these words are used to describe things that aren't dead, we use live as an attributive adjective and alive as a predicative adjective:
The term two-year old is used as an attributive only adjective phrase:
The term two years old is used as a predicative only adjective phrase:
Similarly the following measure phrases only have attributive uses, where the noun part of the phrase has no plural inflection:
as in the following examples:
In contrast, the following measure phrases where the noun part is plurally inflected can only be used predicatively:
Note
We can also use the term two year old as a nominal phrase. We can use it like a noun.:
Notice that we use the attributive adjective here because we mean: a two year old child.
Hope this is helpful!
On the other hand, you could describe a successful tennis player equally as "a five-times winner of the Australian Open" and "a five-time winner of the Australian Open". And the former British government minister John Prescott, who was nicknamed 'Two Jags' (because he had a Jaguar as an official vehicle in addition to the Jaguar he owned), was sometimes referred to as 'Two-Jags Prescott', not 'Two-Jag Prescott'. So the general rule is not absolute.
I think it all goes back to the -a suffix in Old English that marked plural adjectives, but which has since been lost. Perhaps if we'd had one a thousand years ago, we'd have called it A ten pounda note.
Switching from money to weight, some people would ask the grocer for Ten pound of apples. Presumably that's by association with the form we're talking about here, but I imagine most of us would use the plural in this case. So it's certainly not all cut-and-dried.
In short, it seems this is another case of 'language on the move' in ways we don't normally notice.
