Q:

Schools are the only place or schools are the only places?

Consider the sentences below:

"Cinemas are the only places where movies are being played"
"Schools are the only place where teachers teach"

My gut reaction is that "places" should be in plural form. However, when I Googled the second sentence with a singular "place", more results are returned with the plural form "places".
I am confused by it. Could anyone explain to me which one is correct, and why?

A:

As Damkerng T. has helped illustrate:
Which one is correct and why?

Both versions of the sentence are correct. This version:

Schools are the only place where teachers teach

is treating Schools as an ideological category or type. In contrast, this version:

Schools are the only places where teachers teach

is treating them as physical places and/or locations. It would also be permissible to write the entire phrase singular and still be grammatically correct:

School is the only place where teachers teach.

