Ordinarily in English, adjectives directly describe the noun being modified; thus an adjective indicating an emotion attributes that emotion to the noun - "I am happy" means that I am the one experiencing happiness. But if I say "it was a happy day", I am not claiming that the day experienced happiness - it is not a conscious entity. To my mind, these are two entirely separate functions performed by the same word "happy".

In other languages, adjectives (or what might reasonably be labelled as such) commonly work this way - I have often seen native speakers of Chinese or Japanese confuse the English "scared / be afraid" with "scary / be frightening" because (as I understand it) in those languages, both concepts would ordinarily be expressed with the same word, inflected the same way.

Yet as far as I can imagine at the moment, English does this only in very limited cases. I may be scared, but the cause was scary. I may be hungry, but my food is not - and neither is my mealtime, nor anything else related to my proposed solution to hunger.

Am I overlooking something? Is there a term for this way of using adjectives in English, and are there a bunch more examples that aren't coming to mind at the moment? Or is "happy day" just a magical set phrase that I've been using unquestioningly all these years?


When a noun represents a container, whether literal or metaphoric, modifiers can reference the content. Likewise, when a noun names something that plays a functional role, modifiers can reference the agent.


  • running class - class filled with (aspiring) runners, not a class that runs.

  • apple cart

  • delicious plate

  • diving board - board for people to dive from, not a board that dives.

  • smart choice

In your example, the day is metaphorically filled with someone’s happiness. As such, it can be called a “happy day”.

  • Toy gun, a gun filled with ...? Invalid toilet?!? I think the association can be looser than that of the container metaphor. – Edwin Ashworth Mar 6 at 12:44
  • Yes, certainly. I didn’t claim otherwise. – Lawrence Mar 6 at 13:46
  • Running shoes. Though there was the old woman who lived ... – Edwin Ashworth Mar 6 at 15:01
  • Items like "running-shoes" ("shoes for running") and "diving-board" ("board for running") are best treated as compound nouns, not syntactic constructions (modifier+head). – BillJ Mar 8 at 7:31
  • 1
    Correction of typo in second example: "diving" (not "running"). – BillJ Mar 9 at 13:03

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