Originally Posted By: wsieber
What would you say about the following example:
"There are a certain number of insects crawling on the wall" ? Here, the singular would sound very odd to me.


Ok, let's try this one:
There is a certain number of insects crawling on the wall and that number is one.

My point is that "case", meaning nouns or pronouns, must agree in number with singular or plurals verbs and in number with the objects of the verb. Simple huh?