i've never used "ill" in my entire life, also some people will use sick to mean super cool or awesome. example, have you seen the new godzilla movie? it's sick
Sick describes short-term diseases or ailments, like the flu, and is commonly used to refer to a feeling of nausea; Ill is more formal and is used to describe long (cancer, pneumonia...) and short-term (like sick) diseases or ailments...
Why I cannot say "I have one sick cat?" When should I use "a/an" or "one"? What's the difference?
This is a matter of usage and not of grammar. "One" sick cat does not mean the same as "a" sick cat. "One" sick cat is used to mean that the cat is very sick. Generally, we don't say the number when speaking of one item unless we want to emphasize the quantity. In this case, It's not even an emphasis on quantity but, rather an idiomatic phrase.
Unless you have several cats and one of them is sick... Then you might say "I have one sick cat". Also, say someone says "I think your pesky cat scratched my chihuahua in a fight" and you answer "I have one sick cat - no others that could injure your dog". It may not be common, but it's not, in other words, impossible to think of a time when you could say "I have one sick cat" in English. So it should be accepted.
I entered "I have a sick cat." If it was not accepted then, it is now.
Oh no, it works only in English =) In Portuguese you have the literal meaning.
Although I have heard ".....feels poorly." to mean sick, it is not common to hear "poorly" used in a sentence with an indefinite noun.
As a Brit, I'd never say 'I have a sick cat'. In British English, 'sick' means 'vomiting', generally. I'd say 'I have an ill cat' or 'I have a poorly cat'.
You should report it then. In American English, you can simply have a cold and say you are sick or that you are feeling poorly, but if you are ill it is more serious. Although that may be different in different parts of the US as well.