In your headcanon do the Ponies speak English or their own language?

[Le Trotteur Sauvage 13,051]

That's a good question because I do both, I don't know why sometimes they speak French with the voice of the actor, and sometimes for a completely unknown reason they just start speaking in English with the English actor voices... And it doesn't seems to be a logic or anything, it's just random. For exemple, the "yay" of Fluttershy is always in English, such as "so awesome" of Rainbow Dash !

[Tacodidra 61,265]

I have never even thought of them speaking any other language than English. Actually, I have never found it weird to have characters in a fictional universe speak languages from our world (usually English), I guess I'm just used to it.

The writing system in Equestria is a bit weird, as it seems to alternate between English and some nonexistent language. Maybe Equestria is multilingual, but English is the most common language there.

[Thrond 3,263]

Let's just go with lazy fantasy cliche and say they speak the "Common Tongue." 

[Jeric 46,855]

Spoiler

In A Health of Information there be a reference to a dead pony language called Old Ponish when Fluttershy is researching a cure for Swamp Fever. It's possible that one of their modern languages is called Ponish. It makes sense since we usually add the 'Old' modifier to early versions of existing language. 

I say may ... only because the episode was in Russian, and I don't know how accurate the subtitles are yet. 

Spoilers for the next episode above ... may add to this discussion. 

[PlzDelete 2,456]

I can imagine both pretty well. I lean towards the English thing a little more though.  

[EpicEnergy 23,223]

I think they speak English, but there is a language in their universe called ponish, not sure how that differs from English though,

[dead account 2,711]

German, since that's the language I watch the show in.

[They call me Loyalty 1,948]

They neigh in a natural manner, like all equine beast should. So, I imagine them making these guttural noises to communicate with one another.
Not really. I just believe they speak english. I mean, they are humanized animals already. So, there is no much of a leap in logic, considering these miniature horses happen to have a connection with the human world through that magic mirror, and could have learned any human language you can imagine from simply observing their superior counterparts.

[ExplosionMare 18,079]

They speak Ponish but as to what that is actually meant to sound like, we'll never know

[twilightlicious69 629]

In my headcanon, the ponies speak a language like the Houyhnhnms (ya know what I'm talking 'bout right?)

And 'bout Equestria Girls, it's safe to say from FiM point of view that it's not canon. The entire EqG series is a fabricated tale of another parallel world.

[dead account 2,711]

19 minutes ago, Rainbowshine295 said:

In my headcanon, the ponies speak a language like the Houyhnhnms (ya know what I'm talking 'bout right?)

Never heard about it, but I looked it up. How cool is that?! This deserves more research!

[twilightlicious69 629]

26 minutes ago, Sven Seelenherz said:

Never heard about it, but I looked it up. How cool is that?! This deserves more research!

It's from Gulliver's Travels. If you've read the book, then you know how the Houyhnhnms. I can't believe I still remember this!