What is difference between Ill and Sick, How do I say "sick people" or "ill people" to refer to people not feeling well?

  • ill used before a noun means bad or harmful : the neglect and ill treatment of children.....unable to join the army because of ill health... an ill omen...harbor no ill intentions toward them. Dec 5, 2017 at 18:39

2 Answers 2


Honestly, I was not aware of the differences between both either; however, after searching for it for a while, I found out some interesting differences between both:


  • Is normally used to refer to long-term diseases, such as cancer, pneumonia and etc..

  • Can never be used attributively (before the noun) - ex: ill child. Instead, it can only be used postpositively (after the noun) or predicatively (after a linking or copula verb) ex: A child ill - He seems ill.

  • Ill also works as a prefix when implying something made in a bad manner: The ill-painting of my house, we should have never employed that guy!


  • Is an informal and short term, usually refers to short sickness such as one that unables you to go to school for one or two days.

  • Can be used attributively, postpositively and predicatively, ex: I saw a sick child; the child sick; the child seems sick.

  • 1
    But interestingly, "ill" is sometimes used before a noun when it is used metaphorically. "It's an ill wind that blows no good." "Ill-gotten gains", etc.
    – Jay
    Dec 5, 2017 at 20:35
  • Interesting, Jaw. You also reminded me of adding the fact that "ill" also works as a suffix when implying something made in a bad way. I will add it up on my answer.
    – Davyd
    Dec 5, 2017 at 20:56
  • I've never seen unables used like that. Even Scrabble does not allow it, yet the meaning is quite clear. Interesting.
    – Davo
    Dec 5, 2017 at 22:55
  • @Davo - Cambridge cites such uses of the prefix ill: dictionary.cambridge.org/dictionary/english/ill
    – Davyd
    Dec 5, 2017 at 23:17
  • 1
    @Davo Able and unable are not verbs. Conjugating unable as if it were a transitive verb is kind of fun and interesting, but of course, the standard word to use there would be "disables." And then you'd use "from" as the preposition. Dec 5, 2017 at 23:27

Sick and ill are both adjectives that mean ‘not in good health’. We use both sick and ill after a verb such as be, become, feel, look or seem:

I was ill for a time last year, but I’m fine now.

Nancy looks ill. I wonder what’s wrong with her.

I felt sick and had to go home at lunchtime.

We can use sick before a noun but we don’t normally use ill before a noun:

She’s been looking after a sick child this week, so she’s not at work.

Not: … an ill child …

In American English sick means more generally ‘to be unwell’.

Not the answer you're looking for? Browse other questions tagged .