Auto-translate help?

Sorry if this is a repost. Can anyone please explain how to use the auto-translate feature? I'm on PS3 though that should be irrelavent since I use a keyboard. The reason I ask is because recently I used the duty finder (join in progress) and ended up in an Ampador Keep run on a European server. I wanted to explain the boss mechanics to the tank/healer but they spoke french so I was unable to help. We failed due to time constraints. Both myself and the other DPS remained silent the whole run, assuming the other didn't speak french also. Edit: I'm pretty sure that the auto-translate feature won't help explain complex boss mechanics but I'd like to know how to use it anyways.

Start typing a word. Hit tab. Select the AT phrase from the list of matches. Hit enter. Continue on to next word/phrase.

Thanks :) ^^