337.Idioglossia is a phenomenon, incompletely understood at best, where two persons
develop a unique and private language with highly original vocabulary and syntax.

(A) where two persons develop a unique and private language with
(B) when two persons develop a unique and private language having
(C) in which two persons have unique and private language development with
(D) having two persons who develop a unique and private language that has
(E) in which two persons develop a unique and private language with

hi I have narrowed the choices down to A and E, however the only difference between them is the usage of "in which" vs "where". The correct answer is E, but I thought the usage of in which and where is interchangeable.

thanks in advance.

btw. I was a mgmat student.

zxzhou,

We cannot comment on a particular problem unless the source of the problem is cited (book, website, test, question number, etc.)

However, the general grammatical principle is that "where" is used ONLY for actual locations. Similarly, "when" is used ONLY to describe a particular moment in time.

-dan

when do we use "in which"?

For the test, you can generally think of it as: use "in which" when you want to use "where" but it's not a physical location or "when" but it's not a time. :)

"in" is a preposition - you can put lots of different prepositions before which. So you use "in" when you mean either literally or metaphorically located within, or a part of.

"which" is a relative pronoun, so you use it to refer to some other noun elsewhere in the sentence.

The house in which I sleep is cold. I wouldn't say "the house which I sleep is cold" - I'm literally in the house, so I need to say "in which."

There are some situations in which it is preferable to use a pencil rather than a pen. Now, here, I'm not literally within the situation - but I am metaporically.