Halo 5 Guardians – How to View Arena Ratings from Before a Reset

You cannot turn off the light on the shotgun. It is locked on by design as a balancing mechanic, it lets you know that Spartan is holding a shotgun and should not be engaged with in close range. There is a other weapons that use these light giveaway mechanics: Railguns while charging and Sniper weapons.

Covenant and UNSC have translation devices that allow cross-species communications in pretty much all standard issue equipment at this point, but the books mention that the Sangheili can speak English naturally as well by using their mandibles to approximate a jaw. However, it's noted that most of the Sangheili who actually know English find speaking it to be awkward and uncomfortable.

One funny note is Sangheili have trouble saying the letter "P" due to the aforementioned lack of proper jaw and lips -- it ends up as more of an "F" sound. In the Kilo-Five trilogy of books, Phillips is nicknamed "Phyliss" due to him being someone speaking fluent Sangheili and having his name pronounced in this way.