"Peter is in the hospital."
Translation:Péter kórházban van.
What it expresses is more of a state than a location. This sentence suggests that Péter is in the hospital because he is ill or had an accident. If you put in the definite article, it still means that Péter is in the hospital, but it's not clear if he's there as a patient, a guest, or a doctor.
Ah, so translating to British English:
- Péter kórházban van. "Peter is in hospital." (= as a patient)
- Péter a kórházban van. "Peter is in the hospital." (= probably as a visitor, a doctor, a cleaner, ....)
US English usually does not make this distinction with "hospital", I think, using "the hospital" always, even when "the building is used for its intended purpose". (Though it does with some other nouns such as "at school" or "at church".)
Does Hungarian make a similar distinction for "He was taken to hospital." (= because he was in an accident and needs care; no article) and "He was taken to the hospital." (= because he wanted to visit it but needed someone to give him a ride there in a care; with article)?
Yes, the distinction can be expressed in that context too, but maybe it's less clear.
"Kórházba vitték", because he needed care.
"A kórházba vitték" = probably an answer to why Péter got into the car of his friends and where they went. Or he was badly injured, and someone asked if he was taken to the hospital or right to the mortuary. (sorry, I couldn't think of a more pleasant context)
The long explanation for the second sentence was only needed because it's not the most neutral word order and emphasises kórházba. The neutral sentence is "Elvitték a kórházba".
I don't understand why the sentence must contain "van" to be correct. I remember reading that in 1st person singular that you can omit "van". I also read some of the previous conversation. It does surprise me that their translation doesn't have the definite article. I cannot think of an example in American English when we would say someone was " in hospital", only If it were plural, "in hospitals".
There are some sentences where you must omit van and others where you may not omit it.
If you are saying what something is (noun: Peter is a cook, Horses are animals, ....) or what something is like (adjective: Peter is lazy, my horse is fast), then you may not use van.
If you are saying where something is, then you must use van.
This sentence is about where Peter is, so you need the van.