How do you know when to use singular or plural nouns if they're used as adjectives?


32-bit computer vs 32-bits computer?

teacher union vs teachers union?

wedding planner vs weddings planner?

sport medicine vs sports medicine?

student council vs students council?

Which one is correct?

  • 1
    Note that Students' Council and Teachers' Union are both possessive as well as plural.
    – Ben
    Jul 4, 2017 at 9:36
  • It's student council not students council....
    – mike
    Jul 4, 2017 at 12:16
  • 1
    The short answer is "by being an educated native speaker of English" or having lived in an English-speaking country for a long time and have acquired a deep familiarity with usage. Doesn't help does it? That's language.
    – David
    Jul 6, 2017 at 19:41
  • And to illustrate how difficult things are, I would say the singular is teachers' union (a union for teachers), not as you have written it.
    – David
    Jul 6, 2017 at 19:43
  • I've seen this question before.... In the meantime, here's an article from Cambridge dictionary.cambridge.org/de/grammatik/britisch-grammatik/…
    – Mari-Lou A
    Jul 6, 2017 at 20:33

1 Answer 1


You are thinking of noun adjuncts, or attributive nouns.

Both Wikipedia and someone from Pearson Education state that traditionally, all attributive nouns are singular. However, the number of plural attributive nouns have increased over the years in a rather arbitrary manner. This means that there is no longer a set rule to determine whether the attributive is singular or plural.

Despite this, there is a rough guide that you can use.

The attributive noun tends to be plural in the following situations:

1: The singular form might lead to ambiguity

an arts degree (a degree in the humanities) as opposed to an art degree (a degree in fine art)

[I believe that this situation is what is referred to on wikipedia as "lexical restrictions", providing the example of "arm race" vs "arms race"]

2. There is no singular form of a noun (in pluralia tantum)

a customs officer

3. There is a need to denote variety

a soft drinks manufacturer [but] a car manufacturer

4. A topical issue comes forth, often in newspaper stories...

the tapes issue

the tapes compromise

the Watergate tapes affair

the White House tapes mystery

and other examples, including jobs cut.

[I am not entirely sure what the point of this fourth category is]

[Source: Pearson Education , directly quoted apart from what is enclosed inside square brackets]

To this list I add my own:

5. [The attributive noun is plural if] it comes from the possessive form of the word

teachers union

ladies man

However, this is more of an explanation rather than a rule you can use. There are too many exceptions, and you are unlikely to know the origins of the word. It doesn't make sense that it is teachers union but not students council.

Note that we often "choose by ear and it doesn’t matter (employee lounge, employees lounge)" (Chicago Manual of Style).

I would argue that it would be easier to just look it up every time and memorise words instead of trying to find a rule or categorise them. Even as a native speaker, I was not entirely sure whether it was "sport medicine" or "sports medicine" before looking it up. If you find yourself completely lost and without internet, go with the singular form because it is the traditional form and more common.

  • Well, at least one union of teachers is actually genitive: wtulocal6.org, hence the "s." Jul 6, 2017 at 17:37
  • Very good, but "teachers union"? Surely it should be "teachers' union" with plural obviously "teachers' unions" (whatever the illiterate teachers may think).
    – David
    Jul 6, 2017 at 19:45
  • @david I thought I read somewhere that you don't need the apostrophe.... I'll try to find the source again when I have time later today
    – mike
    Jul 6, 2017 at 21:50
  • @Azor-Ahai see above. I'm not sure what you mean by "actually genitive" — isn't that what I said?
    – mike
    Jul 6, 2017 at 21:53
  • @mik_blom Oh, I see what you meant. I was a little confused (the reason is confusing) Jul 6, 2017 at 22:14

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