Regarding the differences between the first to sentences: "...advantage to..." vs "...advantage of..." I don't believe there is a rule or convention to follow to make the distinction more clear. In this case, I think that either sound fine. Don't take this as a rule, but to me, it feels as if I would say "...advantage to..." more often if I am stating the advantage, rather than asking. "Trust me, there are a lot of advantages to doing it this way. It's much easier." Compared to: "What are the advantages of doing it this way? Is it much easier?" Even still, you could still swap out 'of' and 'to' and it would be just fine in either case. Sentence three is incorrect. "It has" implies that there is a subject that these advantages belong to, however that's not the case. We are simply stating that these advantages exist. Sentence four is fine. Hope this helps!

Hello....My preference is the fourth sentence in terms of its structure. However, the first and second sentences are okay as well but the second sentence is more fluent.

*Which of these sentences are grammatically correct? *Which sentence is grammatically correct? There are many advantages to having school experience at a young age. *There are many advantages to having school experiences at a young age. There are many advantages of having school experience at a young age. It has many advantages to have school experience at a young age. Having school experience at a young age has many advantages. *Having school experiences at a young age has many advantages.