I once asked Chris Parnell if he knew spanish since he speaks it a lot in Archer. He said they give them phonetic lines and he doesn’t know any languages besides english.

From what I’ve seen, it depends on how much is being spoken, and very much depends on what the actor is capable of. For a single line, more often than not the actor will learn it phonetically, and just say it themselves. If it’s a whole episode, the actor may accept the challenge, but if confidence isn’t high, they’ll get a sound alike. For full translations, like anime dubs, they get all new actors. But sometimes the same actor will stay and do the other language if they are fluent enough in it to do the job well.

Then there’s Vin Diesel doing all the alternate language versions of his groot line himself, which a lot of people tout as amazing, but I feel like learning how to say one thing in a foreign language, and just saying it with different levels of intensity or cadence, is something that anyone can do, and shouldn’t really be celebrated.

Mostly they would use the original voice actor. It's more of a hassle to find and recruit talent that sounds similar and add them to a payroll, add a line in the credits, schedule voice recording times etc than getting the original to learn a paragraph in a foreign language. It's not hard , like you said, but it's a hassle and it takes time away from several people in different areas.

You would have exceptions of course, perhaps the show has very eccentric producers/directors and enough of a budget but when it comes to resource management a couple minutes of voice dialogue usually isn't worth it.

If you've ever watched anime without dubs where they have to speak English a lot, you'd know lol. Generally IIRC they just have to sound believable enough.

Non animated example: Stargate SG1 did this once and the spoken dialogue was an inside joke., Reportedly, their Russian was terrible since they just used English-speaking extras - not that most English speakers would know. Basically just a couple of Russian soldiers on duty heard a noise, ones asks "what was that?" And the other answers something like "probably just the monster from the end of last season." Then the subtitles have the correct dialogue.

The only example I personally encountered "in the wild" was Disney's Tarzan, where Phil Collins insisted on singing the songs in different languages himself. It was a bit surreal to hear him sing in German, and frankly it is very noticable that it isn't his mother tongue.

Just in case you want to listen to an example: "Son of Man", sung by Collins, in ...

• ...German: https://www.youtube.com/watch?v=AbfGOohwP_4

• ...Spanish: https://www.youtube.com/watch?v=5k8NySrpplY

• ...French: https://www.youtube.com/watch?v=J5Oz2fBXTDs

• ...Italian: https://www.youtube.com/watch?v=1NpGoEpMZh4

On the other hand, I do appreciate the effort. Letting someone else do it would have been easier for him, but instead he sat down and learned a ton of phonetical lines by heart, in four different languages - none of which he understands. For all seven or so voiced songs in the movie.

I don't remember ever seeing them switch out the voice actors.

They just learn the bits in the other language. It's not like it has to be good. Most of the time they totally butcher it, but who cares?

Probably just the voice actors, most of the time the pronunciation sucks. Like in Oppenheimer where he suddenly talks Dutch, just complete gibberish and all the scientists are there smiling and nodding thinking "What an ass, thinks he can learn a language in a few weeks".

That can totally depend on the situation and who's the voice actor. In the case of My Life As A Teenage Robot, I'm pretty sure in the episode where Jenny loses her English voice disk, her voice actor does both her English and Japanese form the whole episode. I could be wrong about that's so feel free to correct me if I am.

Judging by the quality of most of the foreign stuff I've heard the original voice actors do them.

Reminds me of Nodame Cantabile (not a cartoon). It's a Japanese series where later on a German secret agent comes to Japan. It's clearly a Japanese actress in a blonde wig. And she briefly talks to the canonically Japanese student in German. His German is soooo much better than hers. His is almost flawless and hers is atrocious. But she is supposed to be the native speaker.

https://youtu.be/pU9sHwNKc2c?si=DDSnrAzvMQaekdKu This video might give some clarity.