If Harry spoke two or more languages, what would it sound like to him if he talked to a snake?

Question

Before the Horcrux in his body got destroyed, Harry could speak to snakes, right? However, the whole ''conversation'' sounded just like English to him. But if Harry were a bilingual child, which language would the conversation with a snake sound like to him?
If he spoke both French (or any other language, for instance) and English fluently, what would he understand from a snake?
You could argue that the conversation would sound like English, because it is his native language, but what if he were born in a bilingual country?

Answer 1

He would probably hear what he expected to hear

We actually do have a case where Harry hears, if not two languages, at least words from two languages.

As the snake slid swiftly past him, Harry could have sworn a low, hissing voice said, "Brazil, here I come.... Thanksss, amigo."

—Harry Potter and the Sorcerer's Stone

This would seem to indicate that context matters. Obviously, the snake is not speaking Portuguese; it is hissing. It does not actually say "amigo." Nor is it speaking in some regional snake language variant: it was raised in Britain, and in any case Harry only hears one word in Portuguese.

So, why does Harry hear it? Presumably, it's because the snake said something in Parseltongue with the sense of "friend (informal)." He could have heard it as "mate," but he did not, because the snake was Brazilian.

This is a case in which Harry knows at least part of two languages, and hears different ones depending on context.

So I would say that his perception of Parseltongue, if he were truly bilingual, would be determined by the situation he was in. If he were talking to a snake in France, he would expect to hear French, and that is what he would hear. If he were talking to a French sort of snake in Britain, same. If he were talking to a British variety of snake in Britain, he would probably hear English.

If he were talking to a snake in a country where people regularly engaged in code-switching, presumably he would hear the snake doing so as well.

Answer 2

He would understand the snake no matter where the snake was from or what languages he was fluent in.

There are several examples of "Parseltongue" being employed, none of which shared a common thread that would indicate regional dialect or language played any role in the outcome. The boa constrictor example is a "false positive" because of context. However, there are other instances of the language being used in which there were no snakes at all or the reptile was of unknown origin.

Parseltongue can also be imitated, which Ron and Hermione use to enter the Chamber of Secrets. While it's possible that they were "imitating" Parseltongue in the Queen's English, they would have no way of knowing that, as they were not Parselmouths. I could try to imitate Chinese based solely on what I've seen in the movies, but having no knowledge of the language, it would sound nonsensical and, in all probability, offensively racist.

Harry could also understand Nagini. While it can be speculated that Nagini spoke English, having lived among English speaking wizards for so long, her origins are unclear.

During the duel with Draco Malfoy, we are not given any origin for the snake summoned by Draco. Yet Harry was able to communicate with it. We may operate under the assumption that the reptile was summoned from an English speaking country, but an assumption is all it would be.

Lastly, again according to Pottermore, Albus Dumbledore is said to be able to understand, but not speak, "the language". As Pottermore refers to it as THE language [of snakes], we must conclude that it is universal to serpents regardless of their origin and that any Parselmouth could communicate with any serpent.

Answer 3

Animals also speak regional languages, so it is unlikely that snakes have a universal language.

Maybe Parseltongue isn't a language but an encryption format that contains other human languages or sounds. In @Obie2.0's quote, the snake just says the words "Brazil, here I come.... Thanksss, amigo." in 2 languages before encrypted by Parseltongue. No matter what lauguages Harry knows, he only hears (after magical decryption) in the language that the snake originally uses. If it was a Chinese snake, Harry might not be able to understand it.