[Mannosuke]

I've always wondered what the difference between "that" and "which" is.
When should they be used? Is there some sort of criteria behind grammatical correctness?

for example, a statement like

"there have been reports that a huge battleship, which has sunk millions of ships already, has recently crossed the pacific"

I would use WHICH and not THAT, but that's only cause "which" sounds better...lol

[country_pumpkin]

That/ which are relative pronouns. They're used in relative clauses. Which is used for objects, and that is used for both subjests and objests