where is the pair of scissors
where is mother and father
together but reflected upon as a singular
The word "pair" is singular, that's why. If you're asking "Where are the scissors?" or "Where are the parents?" it's plural. Parents = mom and dad.
OK I finally found some reference.
When a compound subject follows the verb and the first element is singular, the verb may be either singular or plural (Merriam-Webster Guide to English Usage)
"is" is accepted now
I keep getting "where is..." marked incorrectly, but it should be accepted.
Can you elaborate why? Are you a native speaker?
I will try to check it on my own, but as far as I remember, plural subject requires "are"... :) I might be wrong :D