As seen in the movie, Durin's Bane made rather unpleasant and irritated growls and roars when awoken.
During the early stages of the world when the Balrogs weren't in hiding, did they have their own dialects to speak like all other beings in Arda (Valar, Elves, Men, Dwarves and Hobbits) and communicate with each other, or were they just there for fearful purposes and have no communication capabilities?
Balrogs are corrupted Maiar. We know that other Maiar can speak (e.g. Gandalf, Sauron). If balrogs can't speak, it would mean they lost that ability in their transformation, which there would need to be evidence of.
Durin's Bane not speaking can definitely be taken as circumstantial evidence, but it needs to be weighed against the other things we know about Balrogs.
Gothmog is called "high-captain of Angband". Captains give orders. Yes, it's possible that Gothmog communicated telepathically, but since there was a spoken language used by Morgoth's servants (Melkian1), it's simpler to assume that Gothmog commuicated via speech.
When Gothmog captured Hurin, the text says he "bound him and dragged him to Angband with mockery." So he was mocking Hurin. The most straightforward interpretation is that it was verbal.
Given those things, I don't see any compelling reason to believe balrogs can't speak.
Why didn't Durin's Bane say anything? Maybe he only spoke Melkian, which he didn't think Gandalf would understand. Maybe that particular Balrog went so long without talking to anyone that he lost the ability to speak. Or maybe he just didn't care to talk.
We know that other Maiar can speak (e.g. Gandalf, Sauron). If balrogs can't speak, it would mean they lost that ability in their transformation, which there would need to be evidence of. sort of imply that orcs would be able to speak elvish, since Orcs were corrupted elves?
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Sep 22, 2016 at 23:00
There are no instances in any of Tolkien's writings of a Balrog speaking, so it's not clear whether they could, or what language they would have spoken. They were, however, definitely able to communicate verbally in some fashion; at the very least, they were capable of making sounds, as Durin's Bane does in the text:
Gandalf lifted his staff, and crying aloud he smote the bridge before him. The staff broke asunder and fell from his hand. A blinding sheet of white flame sprang up. The bridge cracked. Right at the Balrog's feet it broke, and the stone upon which it stood crashed into the gulf, while the rest remained, poised, quivering like a tongue of rock thrust out into emptiness.
With a terrible cry the Balrog fell forward, and its shadow plunged down and vanished.
Fellowship of the Ring Book II Chapter 5: "The Bridge of Khazad-dûm"
It seems somewhat unlikely to me that Maiar spirits, even ones locked in an incarnate form, would be completely unable to speak, especially given their position within Morgoth's forces; even Huan was capable of it, though only on special occasions.
That being said, it's possible that they didn't need the ability to speak; there's evidence that the Ainur were able to communicate telepathically with other creatures. Of course, whether the Balrogs would have retained this ability when locked in their incarnate forms is a question we cannot answer.
From Tolkien's Letters, Letter #210:
The Balrog never speaks or makes any vocal sound at all. Above all he does not laugh or sneer. ... Z[immerman] may think that he knows more about Balrogs than I do, but he cannot expect me to agree with him.
They're never described as talking in any of Tolkien's writings that I could find. However, they can certainly make noises. Some actions can be interpreted as being spoken and some events would be unlikely to have happened without speech, but most of it is circumstantial.
That being said, these are stories born out of a love of language and speech. You'd think Tolkien, a philologist, would have mentioned that a whole group of sentient beings were unable to speak or (worse!) had not developed a form of language.
So there's nothing really concrete, but here's what I found anyway.
Gothmog started as Kosomot, Son of Melko. He was "the 'marshal' of the hosts of Melko". A marshal is usually one of the highest ranks in a military, but it's not a very precise term as its definition has varied across time periods and locations. It would however be difficult to command an army without talking.
In an early name-list, the element -mog is said to mean "voice", as in "Voice of Goth (Morgoth)". This would later change to "strife and hatred", but there's also this footnote:
Nothing is said in any text to suggest that Gothmog played such a role in relation to Morgoth as the interpretation 'Voice of Goth' implies, but nor is anything said to contradict it, and he was from the beginning an important figure in the evil realm and in especial relation to Melko. There is perhaps a reminiscence of 'the Voice of Morgoth' in the Mouth of Sauron', the Black Numenorean who was the Lieutenant of Barad-dur.2 p.67
There are also several passages in the early drafts of The Fall of Gondolin that mention Gothmog bidding or ordering people:
But now Gothmog [...] gathered all his things of iron that could coil themselves around and above all obstacles before them. These he bade pile themselves before the northern gate[...]2 p.176
Then Gothmog Lord of Balrogs gathered all his demons that were about the city and ordered them thus[...]2 p.179
Finally, Gothmog is said to have "mocked" Húrin (mentionned by Ben Osborne above):
Gothmog bound him and dragged him to Angband with mockery.S p.231
Balrogs are said to laugh at Húrin in early drafts of The Lay of the Children of Húrin:
and the Balrogs about him brazen-handed
with flails of flame and forgéd iron
there laughed as they looked on his lonely woe3 p.99
An early draft of The Lord of the Ring has the Balrog hiss just before falling from the bridge:
With a gasping hiss the Balrog sprang up; it seemed to be [?half blind], but it came on and grasped at the wizard.7 p.198
The final text has the Balrog scream:
With a terrible cry the Balrog fell forward[...]I p.434
The Balrog who kills Glorfindel in Gondolin also shrieks:
Then Glorfindel's left hand sought a dirk, and this he thrust up that it pierced the Balrog's belly nigh his own face (for that demon was double his stature); and it shrieked, and fell backwards from the rock[...]2 p.194
References starting with a number refer to a History of Middle-Earth volume, roman numerals to a Lord of the Ring volume and 'S' to The Silmarillion. Page numbers from the Harper Collins editions.
I think you will find this article helpful: http://tolkien.slimy.com/essays/TAB1.html
As usual, we need to turn to the various drafts / sketches / unfinished versions of the legendarium to try to gain insight into what Tolkien was doing.
Various passages in The History of Middle-Earth series show that, indeed, Balrogs could communicate verbally. They were the lieutenants and officers of the orcish armies in the First Age.
A couple of such examples:
"But now Gothmog lord of Balrogs, captain of the hosts of Melko, took counsel and gathered all his things of iron that could coil themselves around and above all obstacles before them. These he bade pile themselves before the northern gate..."
"Then Gothmog Lord of Balrogs gathered all his demons that were about the city and ordered them thus..."
BoLT2, The Fall of Gondolin
