English Spanish French

Were they speaking Portuguese in limbo? I thought that's what I heard, and if so, that's perfect.

This film has actually little to do with heaven, hell, religion, and even God. If you pay attention to some minor details, you can make an interesting conclusion which could explain this kind of allegory.

Note that the Heaven is portrayed in black and white. In one of the first scenes we clearly see the Eiffel tower, what lets us suppose the action takes place in Paris, France (they even speak French there). It is also important to note that Lola's chic, classic performances are no more attended. They have a pretty serious population problem in Heaven.

Everything is very different in Hell. There are no chic performances there, we can only suppose a wide-spread fast-food culture, everyone seems to only seek his own happiness by any means. It's actually a society of gread, money, and violence. And they have no population problem there.

Prior to World War II, French was the language of the intellectual culture all over the world. At some extent, we can still categorize it as such nowadays, compared to English - a language of money, Hollywood, and fast-food culture (the way the Hell is presented).

In other words, nowadays a few people care about slowly decaying classic European culture; but most people prefer industrial, modern American Hollywoodish way of life.

This is my thesis:

Spanish: Easy one, the movie is set in Spain plus the director and most actors are spaniards or mexicans. Wouldn't make sense to see the characters speaking english, german or italian when the movie takes place in Spain.

English: The movie is about the loss of humanity, thanks to the ever-growing materialism, the deification of money, comfort, etc at expense of more important things such as true friendship, spirituality, happiness, etc.
This way of life has been imposed to the middle classes of the entire world by the biggest corporations. And most of those corporations are based on USA OR use english as a lingua franca.
Where do you think would end most CEO's and executives from corporations like Enron, Microsoft, Halliburton, The oil and car companies, Merryl Lynch, Fox News, Wall Street Stockbrockers!. Certainly not in heaven!

French: Represents the romantic past. That's why the "Heaven" scenes are shot in B&W and people wears dresses/suits from the 30's. It represents a sort of lost naïveté.

Latin: is used in the "limbo" both by the demons and angels to communicate with each other while they are attending the trials of the new arrived souls.