But I put tomato sauce on top of my spaghetti (which I imagine a lot of people outside the US call marinara sauce).
No, actually, we'd call it tomato sauce or some variant of "Neopolitan". I think 'marinara' as a term for tomato sauce for spaghetti is actually a US invention. We (and probably the Italians) would expect marinara to have something marine-related in it, like fish or shell-fish.
