Which one is correct :
1/
a) He was in hospital VS in a hospital VS in the hospital ?
b) He was at university VS at a university VS at the university ?
c) He was in prison VS in a prison VS in the prison ?
What are the differences between the presented examples and which of them are completely wrong ?
2/ Why is it so that in a sentence : "Did you read about it in a magazine or in the newspaper" there's IN THE newspaper ? couldn't it be "in a newspaper" ?
3/ Can we say "I must buy a little rice" ? Because as far as I know we can say something like There's only a little water in the jug or "a little cheese"
4/ Why do we have to say "to catch A cold" ? I mean, I know that "cold" is a countable noun but I've never seen anything like "colds" ? Can someone explain me that ? Why do we have to say "to catch flu" without anything before "flu" ?
5/ I don't get the idea of "I was in the shower" and "I was in the garden" while in examples like "I was in prison" and "I was at university" there is no THE... Why, why... oh why :( do we put "the" in the examples above and why we omit it in the latter ones ?
Best wishes,