Board Thread:Destiny Forum/@comment-5650583-20131111135917/@comment-5650583-20140826104732

216.80.140.168 wrote: Unless the Fallen are capable of speaking english then its no problem for communication but when it comes to them speaking their own native languages, then the Guardians are gonna need a translator to interperate on what they're saying.

I think the Guardians might have a translator in thier helmet, or maybe through their Ghost. Either way, the Fallen speaking some English is possible, as it's completely normal to pick up bits and peices of your enemy's language in combat.