Say we have the following sentence :
The further information I need is to know in which building is the class held.
Is it grammatically correct to place "is" where it's placed in the sentence, or should it be moved after the word "class", like this:
...in which building the class is held.
The sentence isn't interrogative, so my guess is the second variant is fine, but sometimes I become quite dubious(this time, for example).
You do need an "is" in your sentence.
The information I need to know in which building is the class held.
Is definitely incomplete. The "is" is part of the direct object - there's no main verb.
SUBJECT: The information that I need to know
PREDICATE VERB: _________(is)_______________
PREDICATE NOUN: (the question itself: "In which building is the class held")
Therefore,
The information I need to know is in which building is the class held.
The given sentence is:
The further information I need is to know in which building is the class held.
The question is: Have I placed the word is in the right place in the sentence?
This question is complicated by the fact that is actually appears twice in the sentence. I've assumed from the explanation in the OP that we are talking about the second instance (which I have highlighted).
Short answer: either is correct. As written, we would read it like this:
The further information I need is to know [this]: in which building is the class held[?] (Here the required information is expressed as a question. The square brackets are the implied elements here.)
If we moved is, it would now read:
The further information I need is [this]: to know in which building the class is held. (Now we are expressing the required information as a statement, a fact to be discovered.)
Of course, if you're not sure, rewrite the sentence. Simplify it.
I need to know one more thing: where is the class being held?
OP has asked which of the following two sentences is correct:
1.The information I need to know in which building is the class held.
2.The information I need to know in which building the class is held.
Sentence 2 is grammatically correct because 'the class is held' is a restrictive relative clause that identifies the building.
If we don't shift "is", proper passive construction is not maintained and the sentence sounds more like a question than a statement.
The sentence is lengthy and hence confusing. It can be be made concise without changing the meaning:
"I need to know in which building the class is held."
