what determines what parts of the talmud(if any) are in hebrew rather than aramaic?

Question

I read in this question

https://english.stackexchange.com/questions/226412/origins-of-turn-over-in-his-grave-turn-over-in-her-grave-etc-etc/226478?noredirect=1#comment576934_226478

That this line in Sora 7b is in Hebrew and not in Aramaic.

In there, in Sotah 7b, it says (in the English translation by Soncino):

All the years that the Israelites were in the wilderness, Judah's bones kept turning in his coffin until Moses arose and begged mercy for him.

And the original Hebrew

כל אותן שנים שהיו ישראל במדבר היו עצמותיו של יהודה מגולגלין בארון עד שעמד משה ובקש עליו רחמים

And that parts of the Talmud Bavli are in Hebrew.

I can guess that the Mishna is in Mishnaic Hebrew, but the passage is from the Gemara

Why is that passage in Hebrew?

And what other parts of the Gemara are in Hebrew?

Is there any order at all as to which parts are Hebrew and which Aramaic?

And where there is hebrew, what's the largest chunk that one gets.. A daf(page)? a masechet(tractate)?

And is it the same with the Talmud Yerushalmi?

And is there any English translation online that states whether what it is translating is Hebrew or Aramaic?