What’s the difference between ILL and SICK?

 Ill and sick – similarities and differences

These two words are practically the same but are used in different situations, there are also differences between British (GB) and American (US) English.

In American English ill is unusual unless it is used in a formal setting.

The British tend to use ill in the sense of ‘unwellafter a verb (predicative position):

  • – Mary wasn’t at school last week because she was ill. (GB)

Americans use sick:

  • – Mary wasn’t at school last week because she was sick. (US)

Before a noun (attributive position) most British people prefer to use sick, as do the Americans.


  • I took special leave from work to look after my sick mother.
  • My girlfriend went to London to visit her sick uncle who had been off work for six months.


Sick is also used to mean vomit (throw up the contents of the stomach through your mouth)

  • – I must have eaten something bad yesterday, I was sick three times last night.
  • – I feel sick. Where’s the bathroom?


It is used to refer to sickness associated with travel in general: travel sick, by boat – seasick, by car –car sick

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2 Responses to “What’s the difference between ILL and SICK?”

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  1. Robert says:

    For some time I have been trying to find a good explanation about this. Thank you for your good work