I am going to reply to several posts. First I'm just going to say the thing about halo is, you have to figure things out for yourself untill the sequel/prequel/catfish. Then it tells you some stuff and leaves you with more to figure out for yourself.
When Johnson was speaking to the prophet in english, maybe it's because:
A. It would make perfect sense for the leaders of the covenant to speak english.
B. Johnson was part of the Spartan I project.
It might not be either though, because:
A. As I think someone said, their bones might be shaped so that they can't speak english.
B. Spartans were originally for combating terrorist threats and rebels, before they discovered the Covenant (although not that long before, as they had colonized planets such as Mars).
I believe that elites had learned english at some point though, maybe after the fall of Reach.
Halo Wars definitely has some truth in it, but it was not made by Bungie. Bungie supported it, but they didn't make it. For one thing, although I haven't read the fall of Reach, I don't think that there were any Brutes in that conflict. I think most of the things in the time-line is true, though I haven't read all of them (black boxes are sneaky).
The reason the arbiter speaks engish with his Covenant budies when your playing as him is obviously so you can understand what he's saying. Unnecessary subtitles can ruin movies, so it could possibly ruin games too.
Cheeks, although I admit that some replies to your topic haven't been very good, you are insulting people even if they make sense. Well, that's all I'm posting for now. Oh, I forgot to add that it's all just opinion, so don't hate someone for having a different opinion. Explain how they could be wrong if you think of something though.
[Edited on 11.15.2009 3:17 AM PST]