When uncertain if refering to multiple or single should the plural form or singular form be used?

If asking a question or giving instruction towards a group of objects where the number is unknown (and possibly could be one) what is the correct way to phrase the sentence? Which of the following sentences are more correct:

Has there been any studies regarding this and if so what has been the conclusion?

OR

Has there been any studies regarding this and if so what have been the conclusions?

Solution 1:

Actually, what I would say is:

Have there been any studies regarding this and if so what were the conclusions?

Think about it this way. Consider the eggs in your fridge. Do you know how many there are? Are you sure there are any at all? Notice that even if we're accepting the possibility that there might just one (or none), the typical question to ask would be, "Are there any eggs in your fridge?" and not "Is there an egg in your fridge?"

Apart from that, when you're talking about research papers, we very often talk about "conclusions" in the plural form: "What were the conclusions of the study?" is far more common than "What was the conclusion of the study?", perhaps in part due to the possible dual meaning of the word "conclusion" in its singular form (you could also be asking about how the study ended).

Solution 2:

Also depends on the "this" that the studies regard. e.g. if you're looking for studies on a general concept like "pizza preferences among college students," you might expect the findings to be numerous. So you would say "what were the conclusions." But if the studies are about a specific question, like, "do college students like pepperoni on their pizza?" then you would expect a single conclusion: yes or no. So you might say "what was the conclusion?"

But yeah both are right as long as you change the first word to "have."