Re 'the cold': it used to be that every disability or illness would be named by the definite article. I remember in one of Jane Austen's novels, Mansfield Park iirc, one character says sympathetically to another "I believe you have the headache"; which today would be "a headache". We still use this form for "the flu", but generally nowadays it is either "a", as above, or with no article, as in "I've got rheumatism rather badly at the moment". I don't know if these are idiomatically similar in US?

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