I for the love of Christ cannot count how many times I've had the Portuguese and Brazilian people in my groups which have resulted in countless fail groups and wipes. The language barrier is just too big to have a successful run. Let me make it clear I ain't saying that they are bad players but from my experience most of them are.
The realms that gets me shuddering are Nemesis, Goldrinn, Ragnaros, Quel' somthing, and a couple others but these few stand out especially Nemesis. Everyone run I've seen someone from Nemesis it has been a bad run. I am currently levelling a druid and most the low level dungeons are suppose to be smooth sailing. However, they ain't. I've never had such a hard time ever before transferring to the Emerald Dream. I transferred off Doomhammer from the Nightfall BG.
And the most annoying part is that even after sending them countless whispers and asking dozens of questions they simply chose to ignore you. Or one of them will simply say, "I am Brazilian. I speak no english". When I don't heal them to get their attention, I usually get a response immediately with one word only.."Heal!!!" It is bearable to a certain extent when the person is a DPS. You can carry the group, however, when it is a tank with 2-3 others from these realms it just becomes too much. I end up dropping the group at the start. In fact, I am always checking the realms of the people in my group at the start of every instance to make sure I don't have any of them.
I mean if Blizzard is focusing so much on PUGS and putting all its efforts in the LFG and LFR function shouldn't it be made smoother and enjoyable to people that use these features? Why can't Blizzard move these realms or at least give some kind of option when queueing for dungeons.
And the most annoying part is that these people make it a point to speak their language in the party chat when 2 or more group together. Like WTF are you thinking????