[MINOR SPOILERS ABOUT CERTAIN MILDLY RELEVANT CONVOS]

Okay, so Atreus in GoW2018 paraphrasing says "You already speak the language, you can read it"

And in Ragnarok they speak of a greek word "υγρός" (Ygros) for humid.

I was wondering, are they in-fiction speaking English? Because at the same time they read norse and then translate it, is that for us the audience?

I'd like to think they're speaking an old form of norse language... that's a cool thought.