I am always confused when using a noun and a gerund as an adjective

For example, do we say swim clothing or swimming clothing, electric generator or electricity generator?

  • There's no general rule for idiomatic expressions (swim suit, electrical generator, carving knife). – John Feltz Jan 16 '17 at 13:28
  • The first two should be hyphenated, "swim-clothing / swimming-clothing". They are compound nouns - single words - so there's no modifiers involved. In "electric generator" and "electricity generator", "electric" and "electricity" are both nominals, not adjectives, modifying "generator". Incidentally, it is far more natural to use one of the compounds "swim-suit" or "swim-wear", than the two examples you gave, – BillJ Jan 16 '17 at 16:31

As John Feltz mentions, most of these are idiomatic and each may be constructed differently. You may just have to memorize the words as individual vocabulary, as you come across them. The two you mention should be:


electric generator.

Again, there is no consistent pattern. For example, we say today is a "work day" (a day when most people work), but two people are a "working couple" (both of them work). You can "lend" someone a "helping hand", but you give them "helpful advice". And so on.

By the way, be careful of some resources online that offer lists of these things. In the hope of providing a reference I came across this site, but it is full of errors.

| improve this answer | |
  • @BillJ what term is appropriate then for phrases and compounds that commonly appear in a particular way that is not deducible from common grammar -- for example, why is it "swimwear" and never "swimming clothing"? I'm honestly curious to know so I can use the right term. Thanks! – Andrew Jan 16 '17 at 19:04
  • 1
    You could call them idiomatic. They're not idioms since the meaning is easily deduced from the component parts. Some people talk of words or expressions being "natural" or otherwise. Neither "swim clothing" nor "swimming clothing" are idiomatic; instead we say "swim-wear" (or "swimwear") or possibly "swimsuit" or "swimming-costume". – BillJ Jan 17 '17 at 9:33

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.