Which one

Jack112 wrote:

Scenario: I have a list of sentences that I have to determine if they are correct. And the book asks me this: 1. For the following sentences, determine which (one) of the following statements is valid. (Is 'one' omitted here?  YES   'is' is referring to 'one' ?  YES   Is this sentence asking me to look for only one correct sentence or more than one?  ONE   If more than one, shouldn't it be #2?)  YES 2. For the following sentences, determine which (ones) of the following statements are valid. (Is this better than #1? Only if there are multiple valid sentences.  For the list of sentences, there are more than one correct sentence, so is this one better than #1? YES  Or both #1 and #2 mean the same thing?)  NO Are they correct? What do these ones mean? 3. For the list of sentences, there is more than one correct sentence. (Is 'list' the subject for 'is' ?) NO 4. For the list of sentences, there are more than one correct sentence. 'are more than one correct sentence' sounds odd to me;  'is more than one' sounds better. For sentence structures like these, I could use either 'are' or 'is' right? 5. The list of sentences are separated by commas. (With 'are' I'm referring to each sentence that is separated by commas?) 6. The list of sentences is separated by commas. (With 'is' I'm referring to the list that is separated by commas?)    Neither of these sound right to me.  The subject of both sentences is the singular 'list'.  It takes a singular verb, and cannot be separated by commas. Only the sentences in the list are plural and are separated by commas. Thanks a bunch!

Jack112 wrote:

5. The list of sentences are separated by commas. (With 'are' I'm referring to each sentence that is separated by commas?) 6. The list of sentences is separated by commas. (With 'is' I'm referring to the list that is separated by commas?)    Neither of these sound right to me.  The subject of both sentences is the singular 'list'.  It takes a singular verb, and cannot be separated by commas. Only the sentences in the list are plural and are separated by commas. How come #1 is right and the subject is not 'vast majority', it is 'cases' and #5 in the quote is wrong? My question is, how exactly do I determine what I use for the subject? What does it depend on? 1. Experts believe the vast majority of cases are caused by a complex combination of genetic and non-genetic influences. 2. Experts believe the vast majority of cases is caused by a complex combination of genetic and non-genetic influences. (This is wrong with 'is' but #5 in the quote is right? Why is that?) Thanks.

EDIT:    We might have to get a grammarian involved on this type of question.  I might offer a guess that list is a different kind of noun than majority.   One is a concrete object, the other is an abstract quantity...carrying perhaps more of an adjectival weight.